Research of Physical Processes in Diamond UV Radiation Sensors Based on Spectral and Current-Voltage Characteristics
The study of the photoelectric properties of diamond sensors is relevant for the development of systems based on them used in various fields. This paper describes the results of experimental studies of these properties. The spectral characteristics of the photosensitivity of diamond UV radiation sensors differ significantly in shape depending on the bias voltage. The data obtained in this work is a series of photosensitivity spectra recorded with insignificant changes in the applied bias voltage from spectrum to spectrum and combined into three-dimensional spectral-current-voltage characteristics. When working with the data obtained, a method has been proposed for studying physical processes in diamond sensors of UV radiation using the normalization of the spectral-volt-ampere characteristics. It is shown that the difference in the spectra is explained by the different contribution to the photocurrent of carriers of different types at different radiation wavelengths. Different types of carriers, electrons and holes, differ in the nature of the saturation of the drift velocity with an increase in the applied field (bias voltage). This makes it possible to establish the degree of contribution of various carriers to the total photocurrent depending on the energy of the incident radiation quanta, as well as to estimate the effect of ionization of impurities on the photocurrent and the character of carrier scattering by them. The difference in spectral characteristics depending on the bias voltage during interband absorption is explained by the influence of the applied field on the surface recombination process.