Photoresponse comparison of indium oxide (In₂O₃) nanomaterials

Abstract

Optical properties of In 2 O 3 nanoparticles coated with polyvinyl-alcohol (PVA) are studied. Compared with uncoated In 2 O 3 nanoparticles, PVA coated sample show enhanced UV-blue emission and suppressed parasitic green emission. Ultraviolet (UV)-blue photodetectors were then fabricated by depositing aluminum (Al) as contacts on top of PVA coated and uncoated samples. The photodetector with PVA coating, exhibits lower dark current and higher responsivity than the photodetector without PVA coating. The rise and fall time of the PVA coated photodetector is about 500 s and 1600 s respectively, one half of the uncoated device. These improvements are attributed to surface passivation of In 2 O 3 nanoparticles by PVA, which reduces the surface defects density and increase free carrier concentration of In 2 O 3 nanoparticles.