The photocurrent across crystalline GaAs p-n junction induced by Nd:YAG laser radiation was investigated experimentally. It is established that the displacement current is dominant at reverse and low forward bias voltages in the case of pulsed excitation. This indicates that hot carriers do not have enough energy to overcome the p-n junction until the forward bias significantly reduces the potential barrier. At a sufficiently high forward bias, the photocurrent is determined by the diffusion of hot carriers across the p-n junction. The current–voltage (I-V) characteristics measured at different crystal lattice temperatures show that the heating of carriers by laser radiation increases with a drop in crystal lattice temperature. This study proposes a novel model for evaluating carrier temperature based on the temperature coefficient of the I-V characteristic. It is demonstrated that the heating of carriers by light diminishes the conversion efficiency of a solar cell, not only through thermalisation but also because of the conflicting interactions between the hot carrier and conventional photocurrents, which exhibit opposite polarities. These findings contribute to an understanding of hot carrier phenomena in photovoltaic devices and may prompt a revision of the intrinsic losses in solar cells.

Microwave Bow-Tie Diodes operate across a broad frequency range, including THz radiation detection and THz imaging applications. When fabricated using modulation-doped structures, these diodes exhibit enhanced detection properties that are best characterized by voltage sensitivity. The sensitivity is influenced by multiple factors, including diode design, semiconductor material quality, and the characteristics of the ohmic contacts. In this study, we examine how the electrical properties of modulation-doped bow-tie diodes are affected by their orientation relative to the crystallographic axes. Extensive investigations on various bow-tie diodes exposed to broadband microwave radiation, both in darkness and under white and infrared light illumination, enabled us to identify the optimal diode designs and illumination conditions for maximizing sensitivity to electromagnetic radiation. Based on our findings, we provide recommendations for diode design and illumination conditions to enhance the diode’s sensitivity to microwave radiation while minimizing illumination-induced effects on electrical properties.