Determination of diffusion length of p-type GaN from spectral-response measurements

An alternative method of extracting diffusion length, L, from the spectral response of a Mg-doped GaN Schottky photodiode using the charge carrier collection probability profile is investigated. The collection probability, phi(z) is defined as the probability that a photogenerated charge carrier at depth z will contribute to the measured short-circuit photocurrent. Using this method, the diffusion length is estimated to be approximately 10 nm.