METHOD OF DETERMINING INTERNAL QUANTUM EFFICIENCY OF SEMICONDUCTOR PHOTODIODE BASED ON CURRENT-VOLTAGE CHARACTERISTICS THEREOF

摘要

FIELD: physics.SUBSTANCE: invention is intended for metrological determination of the internal quantum efficiency of a semiconductor photodiode based on the current-voltage characteristic thereof. The oxide biasing method is the known method of calibrating photodiodes. The efficiency of collecting charges for photocurrent generated in a p+ region needs to be determined in order to describe silicon p+nn+photodiodes. The primary reason for losses in the frontal region is the high rate of electron-hole recombination. This effect is intensified by the presence of positively charged ions which result in a surface electric field. The oxide biasing method is widely used to determine the extent of this effect on the internal quantum efficiency of a diode. The advantage of this method is direct measurement of saturation photocurrent and calculating internal quantum efficiency therefrom. However, this method has a shortcoming which lies in the degradation of the working surface of the semiconductor under the effect of a high negative voltage applied to the surface. The aim of this invention is to provide a method of determining quantum efficiency of a photodiode, which is based on comparing experimentally measured current-voltage characteristics thereof with theoretically calculated characteristics. This aim is achieved by recording to current-voltage characteristics of a photodiode at two different power values of incident laser radiation for which only the ratio is known. Said characteristics are then compared using a developed calculation procedure.EFFECT: simple calibration procedure while maintaining accuracy characteristics of the photodiode.