Silicon Nanowires Based High Performance Ultraviolet Photodetector Developed using AuNPs/SnO2 Nanostructure

In this work, ultraviolet (UV) photodetector was developed using silicon nanowire (SiNWs) based heterojunction to obtain a high-performance device. Here, a heterojunction was prepared using gold nanoparticles (AuNPs), tin oxide (SnO₂) nanoparticles on silicon nanowires (SiNWs) on Si chip. The synthesis of SnO₂ NPs and AuNPs was done using the co-precipitation and Turkevich methods, respectively. The SiNWs were developed by using metal assisted chemical etching (MACE) technique. The prepared materials and their heterojunction structures were characterized using various techniques. The photocurrent response of AuNPs/SnO₂NPs@SiNWs heterojunction structure was measured to be 60μA under self-powered mode. The photodetector showed a high responsivity of 45 mA/W and good detectivity of 0.25 × 10¹² Jones at room temperature. The photodetector also possesses a fast rise/decay time of ~ 60 ms and ~ 110 ms, respectively. The sample was checked continually for three ON/OFF sets of illumination at a regular interval. The high performance of the photodetector can be attributed due to the synergetic effect of plasmonic AuNPs with SnO₂ NPs which shows an enhanced light trapping interactions, leading to maximum absorption of UV radiation. Thus, the results presented in this work hold great promise for the advancement of highly effective miniature UV photodetectors with unique features.