Optoelectrical characterization of a UV–Vis–NIR broadband photodetector based on Tm-doped ZnO

Abstract

This study presents the synthesis and characterization of Tm-doped ZnO particles deposited on n-Si and p-Si substrates using the spin coating technique, resulting in the fabrication of Al/Tm:ZnO/n-Si and Al/Tm:ZnO/p-Si photodetectors. The electrical performance of these photodetectors was systematically assessed through current-voltage (I-V) and current-time (I-t) measurements, conducted across a spectrum of light power intensities and wavelengths. Essential parameters, including the ideality factor, series resistance, and barrier height, were determined to evaluate the operational characteristics of the devices. Comparative analysis unveiled distinct behaviors in sensitivity and detection capability between the two configurations. The Al/Tm:ZnO/n-Si photodetector showed a consistent decline in detection ability as the light power intensity increased, suggesting a significant influence of recombination processes and interlayer defects. In contrast, the Al/Tm:ZnO/p-Si photodetector displayed more intricate variations in detection capability, indicating beneficial interactions at the interface that may mitigate some of the detrimental effects typically associated with elevated light intensity. Furthermore, the Al/Tm:ZnO/p-Si photodetector structure's ability to sustain high responsivity under varying illumination conditions and across a broad wavelength range highlights its promising potential for applications in photonic devices.