Investigation of Thermal Sensitivity and Linearity of Quantum Well-Based Heterojunction Bipolar Transistor

This study investigates variations in quantum well (QW) width and the influence of temperature on the electrical behavior of quantum well heterojunction bipolar transistors (QW-HBTs), reflecting recent interest in thermal sensor technology. We propose a modified charge control model to accurately predict this temperature-dependent current gain behavior. Through experimental and simulation studies, we show that as temperature rises, carriers stored within the QW gain energy to escape, leading to an increase in current gain. The study systematically investigates the impact of QW width on thermal sensitivity and linearity, revealing an optimal compromise at a QW width of 90 Å, particularly in the temperature range of 25 °C–100 °C. At 100 °C, the thermal sensitivity of a QW width of 90 Å is 1.34 mA/°C, with the fitting linearity parameter B equal to 0.67748. This study offers a best structure design that can be applied for the development of high-performance temperature sensors integrated into optoelectronic integrated circuits (OEICs), promising advancements in temperature sensing technologies.