Investigation of hybrid electron extraction architecture via integration of mono-shelled carbon nanotubes (MS-CNT) with perovskite oxide BaSnO3 for beyond 38% efficiency in BaZrSe3 photovoltaic cells

Abstract

This research centers on the numerical modeling and simulation of a photovoltaic cell, using the potential lead-free chalcogenide material, Barium Zirconium Selenide (BaZrSe₃), as the light-harvesting layer. The design integrates mono-shelled carbon nanotube (MS-CNT) with the wide-bandgap perovskite oxide semiconductor Barium Stannate (BaSnO₃) to form an innovative hybrid electron extraction composite layer (EECL), aiming to enhance the performance of the photovoltaic cell. A systematic investigation was conducted employing eight distinct hole extraction layers (HEL) to achieve optimal efficiency in conjunction with the BaSnO₃ electron extraction layer (EEL). This study conducted a comprehensive investigation into device physics, incorporating various optimization strategies to address critical parameters such as layer thickness, bandgap, defect density (both interfacial and bulk), and dopant concentration. Furthermore, the analysis extended to evaluating the effects of temperature, auxiliary resistances (series and shunt), capacitance, conductance, and the Mott-Schottky contact behavior within the proposed model. Our study demonstrates that the proposed FTO/BaSnO₃/MS-CNT/BaZrSe₃/FeS₂ chalcogenide photovoltaic cell (CPC) configuration, integrating mono-shelled carbon nanotubes (MS-CNTs) with the BaSnO₃ electron extraction layer (EEL) and Iron pyrite (FeS₂) as the hole extraction layer, achieves exceptional photovoltaic performance, attaining an optoelectronic conversion efficiency (OECE) of approximately 39.28 % and a short-circuit current density J_sc of 38.96 mA/cm². This performance closely approaches the theoretical Shockley–Queisser limit, highlighting the promising potential of the design. It has been evidenced that mono-shelled carbon nanotubes (MS-CNTs) with a bandgap of 1.1 eV achieve optimal band alignment, promoting efficient charge carrier extraction and contributing to a significant open-circuit voltage (V_oc) of 1.03 V. This work aims to stimulate further experimental investigations, providing essential insights to propel the advancement of chalcogenide photovoltaic cell technology.