ZnO(N)–Spiro-MeOTAD hybrid photodiode: an efficient self-powered fast-response UV (visible) photosensor

Abstract

Organic-inorganic hybrid photo-detectors with a self-sufficient mode of operation represent a research area of great current interest. In most efficient photodetectors and optoelectronic devices compound semiconductors containing toxic elements such as Cd, As, Te, S, Se etc. are used and these are also expensive. Hence there is also a rapidly growing interest in replacing these with environmentally friendly and earth-abundant materials. Herein, we report a facile solution-processed fabrication of a self-powered organic-inorganic hybrid photodetector using n-type oriented ZnO nanorods and p-type Spiro-MeOTAD semiconductor. ZnO is eco-friendly and earth-abundant, and Spiro-MeOTAD is non-hazardous. We show that the latter has far less toxicity than the toxic elements stated above. This visible blind UV photodetector shows high sensitivity (10(2)) and a UV/visible rejection ratio of 300. It also exhibits fast response times of τ(rise) ~ 200 μs and τ(fall) ~ 950 μs. Importantly, with a small modification of nitrogen incorporation in ZnO one can also realize a highly-sensitive self-powered visible light photodetector with at least 1000% (or higher) improvements in quality factors (photocurrent/sensitivity/response time) as compared to previously reported organic-inorganic hybrid photo-detectors based on metal-chalcogenides (CdS-PANI or CuInSe2-P3HT). Interestingly, the broadband sensitivity of such N:ZnO-Spiro-MeOTAD photodiode enables sensing of low intensity (~28 μW cm(-2)) ambient white light with a high photocurrent density of 120 nA cm(-2) making it an efficient ambient white light detector.

Developing Seedless Growth of ZnO Micro/Nanowire Arrays towards ZnO/FeS2/CuI P-I-N Photodiode Application

“…The ZnO-FeS 2 -CuI p-i-n photodiode has a large short-circuit current density J sc of 0.5 mA/cm 2 and a small open-circuit voltage V oc under the AM 1.5 condition. This property makes our p-i-n photodiodes to be feasible for working in a self-power mode49, which has been demonstrated in other photodiodes such as ZnO-Spiro-MeOTAD heterojunction50, ZnO-CuSCN heterojunction51, and ZnO-PbS heterojunction52. The on-off current ratio at zero bias voltage is 31, 16, and 371 for ZnO-CuI, ZnO-FeS 2 and ZnO-FeS 2 -CuI p-i-n photodiodes, respectively.…”

A self-powered ultraviolet photodetector based on solution-processed p-NiO/n-ZnO nanorod array heterojunction

“…[3][4][5][6][7][8][9][10][11][12] These devices, utilizing the existing built-in electric eld to separate the photogenerated electron-hole pairs, can detect the light signals at a zero bias without consuming any external power. 1,2 So far, an external electric eld is commonly applied for most of the photodetectors as the driving force to separate the photogenerated electron-hole pairs, therefore, external power sources are typically needed, which will consume energy, largely increase the system size and thus greatly limit the development of nanoscale devices.…”

Improved electrical transport properties of an n-ZnO nanowire/p-diamond heterojunction

“…Cu 2 O, 16 GaN, 17 graphene, 18 NiO, 7 B-doped diamond lm (BDD) [19][20][21][22] and organic materials, 23 have been exploited as the candidate to replace p-type ZnO semiconductors for the fabrication of pn heterojunctions. Among them, the B-doped diamond lm (bandgap 5.47 eV) is appropriate as a hightemperature p-type conductive material.…”