High Speed Diamond Photoconductive Devices for UV Detection

Abstract

Deep UV visible blind photoconductive devices can be fabricated on polycrystalline CVD diamond, a material that is intrinsically radiation hard and visible blind. However, the performance of detectors fabricated on as-grown material is insufficient to meet the requirements of many laser-based applications. In this paper, it is shown that sequentially applied post-growth treatments can progressively change both the gain and speed of these devices. Charge sensitive deep level transient spectroscopy (Q-DLTS) and transient photoconductivity (TPC) has been used to study the effect of these treatments on the defect structure of our thin film diamond detector material. For the first time, we report the successful operation of a diamond photoconductive device with linear bias and fluence response characteristics at more than 1 kHz at 193 nm.