Wenjing Liu , Zhitao Lin , Hongquan Zhao , Min Xu , Shimao Feng , Yiming Shu , Mingjun Wang , Shuhao Li , Zhili Tong , Pengcheng Zeng , Xianguang Yang , Xuan Shi
{"title":"Bidirectional electric-field control of quantum efficiency in Er3+-doped WSe2 monolayers: Up/down-conversion photonics for tunable optoelectronics","authors":"Wenjing Liu , Zhitao Lin , Hongquan Zhao , Min Xu , Shimao Feng , Yiming Shu , Mingjun Wang , Shuhao Li , Zhili Tong , Pengcheng Zeng , Xianguang Yang , Xuan Shi","doi":"10.1016/j.mssp.2025.110078","DOIUrl":"10.1016/j.mssp.2025.110078","url":null,"abstract":"<div><div>High-concentration erbium-doped WSe<sub>2</sub> monolayer (7.2 at%) is synthesized via in-situ CVD, enabling electric-field-tunable photoluminescence (PL) with enhanced quantum efficiency. Structural characterization results verify the homogeneous incorporation of Er<sup>3+</sup> into the host WSe<sub>2</sub>, while gate-controlled devices reveal bidirectional modulation of up/down-conversion PL. The material exhibits broadband emission from UV to visible and near-infrared under 980 nm excitation, and a distinct 780 nm visible peak under 532 nm excitation. Vertical electric fields suppress PL under positive bias but boost up-conversion efficiency under negative bias. Through first-principles calculations, this is attributed to field-induced bandgap narrowing and enhanced electron-hole symmetry. These factors together promote radiative recombination. Power-dependent PL confirms stable exciton/trion emission, supporting high-power applications. This synergy of rare-earth doping and field engineering advances tunable optoelectronics, including adaptive photodetectors, bioimaging, and energy-efficient cooling systems.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"201 ","pages":"Article 110078"},"PeriodicalIF":4.6,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107123","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lalit Kumar , Guruvandra Singh , R. Bhatt , M. Soharab , Indranil Bhaumik , Dibakar Roy Chowdhury , Mukul Singh , Chitra Gautam , Mukesh Jewariya
{"title":"Comprehensive investigation of the THz response of undoped and 0.03 wt% Fe-doped LiNbO3 single crystals using THz-time domain spectroscopy and Lorentz DHO model","authors":"Lalit Kumar , Guruvandra Singh , R. Bhatt , M. Soharab , Indranil Bhaumik , Dibakar Roy Chowdhury , Mukul Singh , Chitra Gautam , Mukesh Jewariya","doi":"10.1016/j.mssp.2025.110072","DOIUrl":"10.1016/j.mssp.2025.110072","url":null,"abstract":"<div><div>This study presents a comprehensive investigation into the effects of iron (Fe) doping on the optical properties of congruent lithium niobate (LiNbO<sub>3</sub>) single crystals in the THz region, which is the most elusive segment of the electromagnetic spectrum. Lithium niobate is a highly dielectric functional optical material with wide applications in photonics, nonlinear optics, and electro-optic devices. Undoped lithium niobate (LiNbO<sub>3</sub>) and 0.03 wt% iron-doped LiNbO<sub>3</sub> (Fe:LiNbO<sub>3</sub>) z-cut single crystals in congruent composition are grown under identical conditions to ensure consistency in crystal quality. The Czochralski technique is used for growing LiNbO<sub>3</sub> and Fe:LiNbO<sub>3</sub> crystals. Furthermore, the as-grown crystals are subjected to structural investigations using Raman spectroscopy to determine the effect of Fe doping on vibrational modes. Utilizing the terahertz time-domain spectroscopy (THz-TDS), we systematically examine the impact of Fe incorporation on key THz parameters over a broad spectral range of terahertz. Observations indicate that Fe doping significantly modulates its terahertz (THz) response, primarily through modifications in charge carrier dynamics and THz interaction mechanisms. Moreover, the experimental data are successfully modelled using the Lorentz damped harmonic oscillator (DHO) approach. The fitting reveals that the lowest vibrational mode, E(TO1), highly governs the dielectric response of both the undoped and doped crystals in the THz frequency range. These findings provide critical insight into the tunability of LiNbO<sub>3</sub> crystals via transition metal (Fe) doping and provide a valuable reference for the development of advanced THz photonic devices.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"201 ","pages":"Article 110072"},"PeriodicalIF":4.6,"publicationDate":"2025-09-18","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107122","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zilan Wang , Hongling Wu , Haoyang Li , Jiaxuan Yang , Francis C.C. Ling , Lai Wang
{"title":"A practical guide to electrical characterization of interface states: Case studies on SiC and GaN","authors":"Zilan Wang , Hongling Wu , Haoyang Li , Jiaxuan Yang , Francis C.C. Ling , Lai Wang","doi":"10.1016/j.mssp.2025.110050","DOIUrl":"10.1016/j.mssp.2025.110050","url":null,"abstract":"<div><div>SiC and GaN have garnered significant attention from both academia and industry due to their promising applications. However, interface states in these devices have become a critical performance-limiting factor. Furthermore, as novel device architectures continue to evolve, the characterization of interface states presents increasingly complex challenges. Among available techniques, electrical defect characterization methods have emerged as indispensable tools for investigating interface states due to their non-destructive nature, rapid measurement capabilities, cost-effectiveness, and ability to provide comprehensive parameters—including energy distribution, energy levels, and capture cross-sections. This tutorial highlights three widely used electrical characterization techniques for interface state analysis: capacitance-voltage (CV) profiling, the conductance method, and constant-capacitance deep-level transient spectroscopy (CC-DLTS). Each technique has demonstrated value within specific measurement ranges, and practical experience suggests that combining multiple approaches often yields the most reliable results. The discussion includes fundamental principles, implementation considerations, and case studies from actual device measurements, aiming to provide experimental researchers with practical guidance. With a focus on SiC and GaN, this guide seeks to offer actionable starting points for characterizing interface states, particularly for those new to these measurement techniques.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"201 ","pages":"Article 110050"},"PeriodicalIF":4.6,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107127","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Soo Cheol Kang , Jin Chul Cho , Jun-Hwan Shin , Dong Woo Park , Eui Su Lee
{"title":"New insights into I-line stepper based InGaAs/InP double-heterojunction bipolar transistors (DHBTs)","authors":"Soo Cheol Kang , Jin Chul Cho , Jun-Hwan Shin , Dong Woo Park , Eui Su Lee","doi":"10.1016/j.mssp.2025.110076","DOIUrl":"10.1016/j.mssp.2025.110076","url":null,"abstract":"<div><div>InGaAs/InP double heterojunction bipolar transistors (DHBTs) are considered promising candidates for high-frequency power amplifier applications in wireless communication, aerospace, and radar systems. Although emitter scaling is essential to enhance the cut-off frequency (<em>f</em><sub><em>T</em></sub>), the conventional use of electron beam lithography increases process complexity, production cost and reliability issues. As a cost-effective and yield-improving alternative, I-line stepper photolithography has recently regained attention. In this study, an InGaAs/InP DHBT with an emitter width (<em>W</em><sub><em>E</em></sub>) of 1 μm, an emitter length (<em>L</em><sub><em>E</em></sub>) of 10 μm and a base width (<em>W</em><sub><em>B</em></sub>) of 0.5 μm was fabricated using I-line stepper photolithography. By employing optimized epitaxial layers and Ohmic contact formation process, the device exhibits a current gain (<em>β</em>) of 40.7 at <em>V</em><sub><em>CE</em></sub> = 0 V and an open-base common-emitter breakdown voltage (<em>BV</em><sub><em>CEO</em></sub>) of 5.1 V at <em>J</em><sub><em>C</em></sub> = 1 kA/cm<sup>2</sup>. The fabricated InP DHBTs with <em>W</em><sub><em>E</em></sub> = 1 μm demonstrate an <em>f</em><sub><em>T</em></sub> = 262 GHz, indicating potential for applications in ICs operating data rates up to 80 Gbit/s ICs.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"201 ","pages":"Article 110076"},"PeriodicalIF":4.6,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106542","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Min Huang , Hao Cui , Xin He , Hang Zhao , Zhiming Shi , Mingjin Yang
{"title":"Metal oxide-modified Janus HfSSe monolayers for SF6 decomposition gas detection: A DFT investigation","authors":"Min Huang , Hao Cui , Xin He , Hang Zhao , Zhiming Shi , Mingjin Yang","doi":"10.1016/j.mssp.2025.110055","DOIUrl":"10.1016/j.mssp.2025.110055","url":null,"abstract":"<div><div>Accurate detection of gases in gas-insulated switchgear (GIS) is essential for maintaining the safe and stable operation of power systems. Density functional theory (DFT) was employed to investigate the adsorption behavior of typical SF<sub>6</sub> decomposition gases (H<sub>2</sub>S, SO<sub>2</sub>, SOF<sub>2</sub>, and SO<sub>2</sub>F<sub>2</sub>) on NiO-, ZnO-, and Ag<sub>2</sub>O-modified Janus HfSSe monolayers. All three metal oxides preferentially bind to sulfur sites on the HfSSe surface, forming energetically stable configurations. These modifications significantly enhance the monolayer's conductivity, yielding reduced band gaps of 0.45 eV (NiO), 0.42 eV (ZnO), and 0.37 eV (Ag<sub>2</sub>O), while simultaneously improving sensitivity and selectivity toward the target gases. At room temperature (298 K), NiO-HfSSe exhibits favorable desorption times for H<sub>2</sub>S (6.38 s), SO<sub>2</sub> (2.95 s), and SOF<sub>2</sub> (0.03 s), whereas ZnO- and Ag<sub>2</sub>O-HfSSe show optimal desorption for SO<sub>2</sub> at 0.58 s and 15.67 s, respectively. Combined with short recovery times and significant band gap modulation, NiO-, ZnO-, and Ag<sub>2</sub>O-modified HfSSe monolayers demonstrate strong potential as reusable, room-temperature gas sensors. This study provides theoretical insight into the application of these modified monolayers for evaluating the insulation status of GIS equipment, laying the groundwork for future experimental validation and optimization of monolayer-based sensors in practical GIS monitoring applications.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"201 ","pages":"Article 110055"},"PeriodicalIF":4.6,"publicationDate":"2025-09-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106541","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Jacob Wekalao , Ahmed Mehaney , May Bin-Jumah , Nassir Saad Alarifi , Mostafa R. Abukhadra , Hussein A. Elsayed , Amuthakkannan Rajakannu , K. Vijayalakshmi
{"title":"A high-sensitivity terahertz SPR biosensor with machine learning optimization for colorectal cancer detection","authors":"Jacob Wekalao , Ahmed Mehaney , May Bin-Jumah , Nassir Saad Alarifi , Mostafa R. Abukhadra , Hussein A. Elsayed , Amuthakkannan Rajakannu , K. Vijayalakshmi","doi":"10.1016/j.mssp.2025.110064","DOIUrl":"10.1016/j.mssp.2025.110064","url":null,"abstract":"<div><div>This study presents a terahertz-based surface plasmon resonance (SPR) sensor developed for colorectal cancer detection. The device employs a distinctive multi-resonator design that integrates gold, silver, and graphene. Structurally, the sensor comprises an elliptical ring resonator coated with silver, surrounded by a gold-coated circular ring on a silicon dioxide substrate, while a graphene layer is incorporated to enhance sensing performance. Performance analysis was conducted using COMSOL Multiphysics simulations under varying conditions, including graphene chemical potential, incident angles, and resonator dimensions. The proposed sensor demonstrated a maximum sensitivity of 1100 GHz/RIU across a refractive index range of 1.329–1.348 RIU, achieving an optimal figure of merit of 17.460 RIU<sup>−1</sup> at 0.719 THz. Additionally, a Random Forest Regression model was used to optimize sensor parameters, achieving up to 100 % accuracy in predicting sensor responses. The device also demonstrated potential as a 2-bit binary encoder, highlighting its versatility for both biosensing and data encoding applications.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"201 ","pages":"Article 110064"},"PeriodicalIF":4.6,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106539","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Fe3O4@PEG/Ag nanocomposite with improved HER activity for Raman and upconversion spectroscopy-based dual-mode enhancer","authors":"Abhishek Kumar Soni, Najeena K S, Kirti","doi":"10.1016/j.mssp.2025.110069","DOIUrl":"10.1016/j.mssp.2025.110069","url":null,"abstract":"<div><div>Raman and upconversion spectroscopy signals are inherently weak due to scattering and nonlinear optical effects. To enhance Raman and upconversion spectroscopy signals, silver (Ag) incorporated nanocomposites are currently in demand due to their better synergistic enhancement strategies through surface plasmon resonance (SPR). Fe<sub>3</sub>O<sub>4</sub>@PEG/Ag nanocomposite has been synthesized and characterized by using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), UV–visible, Field Emission Scanning Electron Microscopy (FESEM), Energy dispersive X-ray spectroscopy (EDS), Zeta potential, Fluorescence microscopy, and Raman spectroscopy. Fe<sub>3</sub>O<sub>4</sub>@PEG/Ag nanocomposite-based substrate shows dual-mode Raman and upconversion enhancer capability by probing RhB and Er<sub>2</sub>O<sub>3</sub>, respectively. Raman enhancer study has been done by monitoring the RhB characteristic peak at ∼1660 cm<sup>−1</sup> and explained on the basis of surface-enhanced Raman scattering (SERS) under a 532 nm green laser irradiation. Whereas, in the upconversion emission study, an improved Er<sup>3+</sup> ion transition is detected under 980 nm NIR laser diode excitation via multiphoton absorption. Interestingly, amplification of the signal intensity has been achieved, as SERS with low fluorescence background under green laser excitation and improved upconversion arise from the nonlinear optical effects due to the interaction of 980 nm NIR laser photons with the surface plasmon resonance of Ag ions available in the Fe<sub>3</sub>O<sub>4</sub>@PEG/Ag nanocomposite. Improved HER activity of Fe<sub>3</sub>O<sub>4</sub>@PEG/Ag with a lower overpotential value (230 mV) as compared to Fe<sub>3</sub>O<sub>4</sub> has been obtained by electrocatalytic performance. Experimental studies carried out in this work show that the synthesized Fe<sub>3</sub>O<sub>4</sub>@PEG/Ag nanocomposite with improved HER activity may be suitable for next-generation Raman and upconversion spectroscopy-based dual-mode enhancer.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"201 ","pages":"Article 110069"},"PeriodicalIF":4.6,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145107129","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Study on substitutional doped GaSe monolayers using hybrid functional: Electronic, optoelectronic, and photocatalytic applications","authors":"Mohamed M. Fadlallah , Safwat Abdel-Azeim","doi":"10.1016/j.mssp.2025.110068","DOIUrl":"10.1016/j.mssp.2025.110068","url":null,"abstract":"<div><div>GaSe monolayer suffers in electronic and photocatalytic applications due to its large bandgap (3.50 eV). In this study, we employed the hybrid density functional, the Heyd-Scuseria-Ernzerhof hybrid (HSE), to explore the effect of substitutional metal single doping (M = Sc, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Ge, As, In, Sn, Sb) at the Ga-site on the structural stability, electronic, magnetic, optical, and photocatalytic properties. Our findings indicate that the bond lengths M-Ga/Se increase as the atomic radius of the dopant increases. Most of the doped structures are found to be thermodynamically stable. The introduction of metal and non-metal dopants significantly alters the magnetic properties of GaSe nanosheets, with dopings of Ti, V, Cr, Mn, Fe, Ni, and Co, as well as Zn, resulting in diluted magnetic semiconductors. In contrast, dopings with Sc, Cu, As, In, and Sb maintained semiconductor characteristics. The As- and Sb-doping resulted in the narrowest bandgap of 2.1 eV, while Ge- and Sn-doped GaSe monolayers revealed promise for two-dimensional spintronic applications. Although most dopants enhanced visible-light absorption, many proved unsuitable for photocatalysis due to the created mid-gap states and unfavorable valence band edges. The study showed that V-doped GaSe monolayer is a promising two-dimensional material for photocatalytic water-splitting and CO<sub>2</sub> reduction under visible light, making it a potential material for clean fuel production.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"201 ","pages":"Article 110068"},"PeriodicalIF":4.6,"publicationDate":"2025-09-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145106540","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Zhitian Shi , Konstantins Jefimovs , Joan Vila-Comamala , Alexandre Pereira , Daniel Josell , Marco Stampanoni , Lucia Romano
{"title":"Deep-reactive-ion-etching in X-ray grating fabrication: a review","authors":"Zhitian Shi , Konstantins Jefimovs , Joan Vila-Comamala , Alexandre Pereira , Daniel Josell , Marco Stampanoni , Lucia Romano","doi":"10.1016/j.mssp.2025.110041","DOIUrl":"10.1016/j.mssp.2025.110041","url":null,"abstract":"<div><div>The development of grating fabrication shares its journey with the development of X-ray phase contrast imaging. Indeed, the fabrication of gratings with features of sufficiently high aspect ratio is one of the bottlenecks preventing the widespread application of phase contrast imaging in X-ray diagnostics, material science and security. The silicon platform that underlies modern manufacture of integrated circuits, with its well-established technologies for lithography, etching and metal deposition, has the potential to provide high yields and volumes for industrial fabrication of both phase and absorption gratings used in a grating-based X-ray imaging systems. This review article introduces recent developments in the fabrication of high aspect ratio X-ray gratings using ubiquitous clean-room manufacturing tools, focusing on deep reactive ion etching processes. It summarizes the most challenging issues for fabricating features with aspect ratios reaching 70:1, proposing approaches to overcome processing problems and improve product quality.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"201 ","pages":"Article 110041"},"PeriodicalIF":4.6,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145060290","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Junyeop Yoo , EunJeong Lee , Sejoong Kim , Ming-Chou Chen , Choongik Kim , SungYong Seo
{"title":"Molecular engineering of acetylenic dithieno[3,2-b:2′,3′-d]thiophene derivatives for organic field-effect transistors","authors":"Junyeop Yoo , EunJeong Lee , Sejoong Kim , Ming-Chou Chen , Choongik Kim , SungYong Seo","doi":"10.1016/j.mssp.2025.110051","DOIUrl":"10.1016/j.mssp.2025.110051","url":null,"abstract":"<div><div>In this study, we report a series of dithieno[3,2-b:2′,3′-d]thiophene (DTT)-based small molecules featuring five different end-capping substituents: 2-octyl-6-(5-(phenylethynyl)thiophen-2-yl)dithieno[3,2-b:2′,3′-d]thiophene (compound <strong>1</strong>), triisopropyl((5-(6-octyldithieno[3,2-b:2′,3′-d]thiophen-2-yl)thiophen-2-yl)ethynyl)silane (compound <strong>2</strong>), 2-octyl-6-(5-(thiophen-2-ylethynyl)thiophen-2-yl)dithieno[3,2-b:2′,3′-d]thiophene (compound <strong>3</strong>), 2-octyl-6-(5-((5-octylthiophen-2-yl)ethynyl)thiophen-2-yl)dithieno[3,2-b:2′,3′-d]thiophene (compound <strong>4</strong>), and 2-(5-((5-(2-ethylhexyl)thiophen-2-yl)ethynyl)thiophen-2-yl)-6-octyldithieno[3,2-b:2′,3′-d]thiophene (compound <strong>5</strong>). To enhance solubility, one-sided linear octyl chain was introduced on the DTT core, while extended π-conjugation was achieved through the incorporation of additional thiophene rings and acetylenic linkages to promote effective charge transport. The thermal stability, optical absorption, and redox characteristics of the synthesized molecules were studied via thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), UV–vis spectroscopy, and cyclic voltammetry (CV). The DTT thin films formed via solution shearing were characterized by atomic force microscopy (AFM) and X-ray diffraction (XRD) to examine surface topology and molecular arrangement. When implemented as active materials in organic field-effect transistors (OFETs), all five compounds displayed p-type semiconducting behavior. Among them, compound <strong>3</strong>, which possesses a thienyl terminal group without bulky alkyl side chains, exhibited the most favorable charge transport characteristics under ambient atmosphere, attaining a carrier mobility of 0.036 cm<sup>2</sup> V<sup>−1</sup> s<sup>−1</sup> and an on/off current ratio above 10<sup>6</sup>. These observations underscore the importance of rational side-chain modification in optimizing molecular assembly and film crystallinity to enhance OFET performance.</div></div>","PeriodicalId":18240,"journal":{"name":"Materials Science in Semiconductor Processing","volume":"201 ","pages":"Article 110051"},"PeriodicalIF":4.6,"publicationDate":"2025-09-15","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145060295","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":3,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}