High Sensitive Ultraviolet Organic-Inorganic Hybrid Photodetectors On Znsse Grown On P-Gaas With Transparent Conducting Polymer Window-Layer

We have developed organic-inorganic hybrid Schottky-type photodetectors with conducting polymer as a window layer on ZnSSe/p-GaAs wafers. Photodetector wafers used in this study were grown by molecular beam epitaxy (MBE). We used poly (3,4-ethylenedioxy-thiophene): poly (styrenesulfonate) (PEDOT:PSS) as conducting polymer window layers formed by spin coating technique on the semiconductor ZnSSe layers. We have succeeded in fabrication of new polymer/ZnSSe structure photodiodes on p-GaAs substrates. The present device has exhibited very high blue-ultraviolet external quantum efficiency eta(ex) = 68 similar to 87 % without anti-reflection coating. The external quantum efficiency in the UV region is eta(ex) = 81 % (wavelength: 300 nm), which is higher than that of commercial Si UV-photodiode of eta(ex) = 54 %. Furthermore, the device exhibits deep UV quantum efficiency eta(ex) = 71 % (wavelength: 250 nm). A dark current density is as low as 10 pA/mm(2) at a reverse bias voltage of 10 V by using Pt guard-ring structure. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim