Photoresponse in thin films of WO3 grown by pulsed laser deposition

Abstract

We report, the photoresponse behaviour of Tungsten trioxide (WO3) films of different surface morphology, grown by using pulsed laser deposition (PLD). The Growth parameters for PLD were changed for two substrates SiO2/Si (SO) and SrTiO3 (STO), such a way which, result nanocrystalline film on SO and needle like structured film on STO. The photoresponse is greatly modified in these two films because of two different surface morphologies. The nanocrystalline film (film on SO) shows distinct photocurrent (PC) ON/OFF states when light was turned on/off, the enhancement of PC is ∼27%. Whereas, the film with needle like structure (film on STO) exhibits significantly enhanced persistent photocurrent even in light off condition, in this case, the enhancement of PC ∼ 50% at room temperature at lowest wavelength (λ = 360 nm) at a nominal bias voltage of 0.1 V.

Quantitative characterization of the long-term charge storage of a ZnO-based nanorod array film through persistent photoconductance

“…When the UV light is off, carriers will disappear through direct recombination (eqn (14)) and indirect recombination assisted by V O 2+ (eqn (15)). The photoionized V O + traps the free electrons (eqn (16)). The donor-acceptor transition involving V O + and V Zn À rapidly consumes carriers (eqn (17)).…”

“…, sub-process (15); photogenerated electrons are captured by photoionized V O + , sub-process (16); donor-acceptor transition involving V O + and V Zn À , sub-process (17); photogenerated electrons captured by surface adsorbed oxygen molecules, sub-process (18); the recombination of free holes and electrons captured by Cu 0…”

Redistribution of native defects and photoconductivity in ZnO under pressure

“…2(c)) the rise and decay edges with two time components for the quantitative analysis of the response time scales. 49 The fast responses were attributed to the rapid change in carrier concentration when the light turned on or off. The slow responses were due to carrier-trapping and detrapping at native defects.…”

Coloring and Bleaching Properties of 500–1000 nm‐Thick Electrochromic Tungsten Oxide Films Deposited by Reactive Direct Current Magnetron Sputtering

“…[16] Lee et al reported that the coloration efficiency increased as the substoichiometry increased. [17] Several deposition techniques such as evaporation, [18,19] anodization, [20,21] pulsed laser deposition, [22,23] pulsed spray pyrolysis, [24,25] the solÀgel method, [26] and sputtering [27][28][29][30][31] have been considered for WO 3 fabrication. Sputtering is most often used due to its simplicity, relatively low cost, and ability to produce good-quality films.…”