%0 Journal Article %J Solid-State Electron. (UK) %D 2005 %T Surface-layer damage and responsivity in sputtered-ITO/p-GaN Schottky-barrier photodiodes %A Pulfrey, D L %A Parish, G %A Wee, D %A Nener, B D %K carrier lifetime;carrier mobility;gallium compounds;III-V semiconductors;indium compounds;minority carriers;photodiodes;Schottky diodes;sputtering; %P 1969 - 73 %U http://dx.doi.org/10.1016/j.sse.2005.09.013 %V 49 %X It is postulated that donor-like nitrogen vacancies, caused by the sputtering of a Schottky-barrier metal onto p-type gallium nitride, diffuse into the GaN and form a surface layer in which both the minority-carrier lifetime and mobility are drastically reduced. Such a damaged surface layer is shown to reduce the responsivity of p-GaN Schottky-barrier photodiodes, thereby offering an explanation for the responsivity values in the range of 0.03-0.04A/W that have been measured in experimental ITO/p-GaN devices. On making allowance for the damaged surface layer, an electron diffusion length of around 300nm can be inferred for the undamaged p-GaN region. [All rights reserved Elsevier] %Z surface-layer damage;sputtered-ITO Schottky-barrier photodiodes;p-GaN Schottky-barrier photodiodes;donor-like nitrogen vacancy;Schottky-barrier metal;p-type gallium nitride;minority-carrier lifetime;damaged surface layer;responsivity value;electron diffusion length;minority carrier diffusion length;InSnO-GaN; %9 article