Mn4Si7-Si〈Mn〉-Mn4Si7 and Mn4Si7-Si〈Mn〉-M photodiodes
Abstract
The current-voltage characteristics of Mn4Si7-Si〈Mn〉-Mn4Si7 and Mn4Si7-Si〈Mn〉-M photodiodes are studied experimentally. The current passage mechanism under illumination with hν ≥ E g is considered. The role of a contact to Mn4Si7 in the provision of high photosensitivity under illumination of the base by light with hν ≥ 1.14 eV at low temperatures, 77–220 K, is analyzed. From electrical measurements, electron microscopic data for the Mn4Si7-Si〈Mn〉 interface, and photocurrent-voltage characteristics, a band diagram under the conditions of photocurrent passage is constructed. The high low-temperature photosensitivity of the diodes (I ph/I d ≥ 109) is explained by the impact-ionization-induced modulation of the base conductivity and injection amplification of holes in the transition layer.