24.04.15 KB. OK to add published OA paper to spira

We demonstrate hybrid photovoltaic (PV) cells based on n-i-p heterojunctions with incorporated zinc oxide (ZnO) films using a sol-gel method. The cells, employing stibnite (Sb 2 S 3 ), and poly(3-hexylthiophene) (P3HT) materials, as light absorption layers, constitute an active region in the indium tin oxide (ITO)/ ZnO(n)/Sb 2 S 3 (i)/P3HT(p)/Ag hybrid structure. Our investigation shows that annealing temperature has a significant effect on both the crystallinity and optical absorption of Sb 2 S 3 films. The near-intrinsic Sb 2 S 3 films annealed at 300 8C exhibits dark conductivity of 1.42 Â 10 À7 S cm À1 . The performance of PV cells strongly depends on thermal treatment of Sb 2 S 3 , and on the thickness of both the Sb 2 S 3 and P3HT layers. Electronic structures of annealed Sb 2 S 3 films was further studied by photoelectron spectroscopy to understand the physics behind.

We study the solar power conversion efficiency in hybrid solar cells based on zinc oxide (ZnO)/antimony trisulfide (Sb2S3)/poly-3(hexylthiophene) heterojunctions. The incorporation of ZnO nanowire arrays (NAs) structure results in power conversion efficiency of 2.9%, or 20% higher than the control device. Absorption spectra and numerical simulation analysis provide strong evidence revealing that the enhanced performance is mainly induced by (1) enhanced optical absorption from light-trapping effect of NAs and (2) reduced bulk recombination rate in Sb2S3 from shortened electron injection pathway into ZnO. Significantly, numerical simulations show that the expected interface recombination increase from larger interfacial area effects is negligible.

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In this paper, we report a fabrication, characterization and stability study of p-GaN/n-ZnO nanorod heterojunction light-emitting devices (LEDs). The LEDs were assembled from arrays of n-ZnO vertical nanorods epitaxially grown on p-GaN. LEDs showed bright electroluminescence in blue (440 nm), although weaker violet (372 nm) and green-yellow (550 nm) spectral components were also observed. The device characteristics are generally stable and reproducible. The LEDs have a low turn-on voltage (∼5 V). The electroluminescence (EL) is intense enough to be noticed by the naked eye, at an injection current as low as ∼ 40 µA (2.1 × 10(-2) A cm(-2) at 7 V bias). Analysis of the materials, electrical and EL investigations point to the role of a high quality of p-n nano-heterojunction which facilitates a large rectification ratio (320) and a stable reverse current of 2.8 µA (1.4 × 10(-3) A cm(-2) at 5 V). Stability of EL characteristics was investigated in detail. EL intensity showed systematic degradation over a short duration when the LED was bias-stressed at 30 V. At smaller bias (<20 V) LEDs tend to show a stable and repeatable EL characteristic. Thus a simple low temperature solution growth method was successfully exploited to realize nanorod/film heterojunction LED devices with predictable characteristics.