The low-temperature solution-process growth of c-axis aligned single crystalline ferroelectric SbSI nanorods arrays by nanosphere lithography for photovoltaic and photodetection applications

Abstract

In this study, we successfully deposited high-density c-axis oriented SbSI nanorod array thin films via a low-temperature (~60°C) solution process coupled with nanosphere lithography (NSL). The NSL provide templated substrates with nano-sized pits for nucleation, followed by controlled growth of c-axis aligned single crystalline ferroelectric SbSI nanorods with adjusting reaction times: individual nanorods (t = 10 min, length = 2 μm) - dispersed flower-like structures (t = 1 h, length = 4.5 μm) - low-density nanorods (t = 4 h, length = 11 μm) - uniformly sized vertical nanorod arrays (t = 12 h, length = 17 μm). The constructed n-i-p structure solar cell (FTO/TiO₂/SbSI/HTM/graphene) shows ferroelectric photovoltaic (FPV) effect: the pre-poling operation with +2 V induce a 27% enhancement in PCE compared to the virginal state. At low-intensity light irradiance (@520 nm, 3.14 mW/cm²) a maximum PCE of 2.9% is obtained, compared to the PCE=0.8% under AM 1.5 G (100 mW/cm²), show its potential for indoor photovoltaic application. As a photodetector working in photovoltaic mode, the device show the maximum self-powered responsivity of 68.55 mA W^-1(@520 nm, 12.56 mW/cm²) and the corresponding specific detectivity reaches to 2.17*10¹³ Jones.