Photoelectrical Properties Investigated on Individual Si Nanowires and Their Size Dependence

Abstract Periodically ordered arrays of vertically aligned Si nanowires (Si NWs) are successfully fabricated with controllable diameters and lengths. Their photoconductive properties investigated by atomic force microscopy (PCAFM) on individual nanowires. The results show that the photocurrent NWs increases significantly laser intensity, indicating have good photoconductance photoresponse capability. This photoenhanced conductance can be attributed to photoinduced Schottky barrier change, confirmed I–V curve analyses. On other hand, electrostatic (EFM) indicate a large number photogenerated charges trapped in under irradiation, leading lowering height. Moreover, size dependence is studied different It found increasing magnitude intensity greatly relevant nanowires’ diameter length. smaller shorter lengths display better properties, which agrees well size-dependent height variation induced charges. With optimized length, great photoelectrical achieved NWs. Overall, this study systematically PCAFM EFM, providing important information for optimization nanostructures practical applications.