Gamma Ray and Neutron Radiation Effects on the Electrical and Structural Properties of n-ZnO/p-CuGaO₂ Schottky Diode

Abstract

Solar assisted heat pump (SAHP) system integrates a solar thermal energy source with a heat pump. This technique is a very fundamental concept, especially for drying applications. By combining a solar thermal energy source such as solar thermal collectors and a heat pump dryer will assist in reducing the operation cost of drying and producing products with high quality. Many review papers in the literature evaluated the R&D aspects of solar-assisted heat pump dryers (SAHPD). This critical review paper studies some of the researches conducted in this field to understand and provides an update on recent developments in SAHPD. Also, a detailed explanation of principles and operation for SAHPD and its applications are presented. The used types of solar thermal collectors, as well as various heat pump dryers, are all discussed in this article. Finally, it is concluded that there is a clear lack of research in the techno-economic and environmental evaluation, while most of SAHPD studies focused on the performance study of the system. Keywords heat pump, collector, two phases, refrigerant, compression index. Nomenclature Volumetric efficiency Mass flow rate Mass refrigerant flow Ts Wetted surface temperature P Pressure Uwi Combined coefficient of heat transfer for tube wall, refrigerant and water film V Velocity k Compression index absolute humidity ratio

Finite Element Analysis of Radiation Effects on Metal Oxide based Semiconductor (MOS) for Space Borne Application

“…The series resistance, "RS", and the ideality factor, "n", are crucial parameters that indicate the electrical characteristics of the diodes. These values can be determined using the equation [2,16,17]:…”

“…Additionally, atomic displacement, which results from irradiation and produces primary knock-on atoms (PKA), leads to lattice defects [22,23,24]. Studies have shown that exposure of ZnO-based semiconductors to gamma radiation results in a deterioration of their electrical parameters, as evidenced by a decrease in turn-on voltage, which is caused by structural defects present in the semiconductor, leading to an increase in its ideality factor [1,2,24,25]. These alterations can also be attributed to the combined effects of the creation of interface states and the generation of electron-hole pairs in the insulating layer.…”

“…ZnO possesses a wide bandgap of 3.34 eV at room temperature and a binding energy in the UV-A region (320-400 nm), along with attractive attributes such as a large surface area, low toxicity, chemical stability, electrochemical activity, and excellent conductivity [1][2] [3]. Furthermore, CuGaO2 and Cu2O have the potential to form heterojunctions with ZnO-based semiconductors because of their low lattice mismatch [2]. Previous studies have revealed that ZnO films exposed to radiation from Cobalt-60 (Co-60) showed a decline in turn-on voltage and lowfrequency noise [4,5], but an increase in electron mobility.…”