The effects of Ppy-silicene composite on the performance of n-/p-type silicon semiconductor-based photodiodes

Abstract

The advancement of electronic technology is accelerated by the discovery of two-dimensional materials, and it also becomes a prompting area for researchers to focus on exploring their alternatives. In these research activities, silicene attracts significant attention due to its potential in various electronic applications. In addition, polypyrrole (PPy), belonging to the class of intrinsic conducting polymers, is another important material preferentially used in this technology. In this study, a composite material prepared in the form of Ppy:silicene is applied between metal and semiconductor. The resulting Ppy:silicene/p-Si and Ppy:silicene/n-Si photodiodes are discussed according to their diode responses. Structural characteristics of fabricated silicene based layer material are determined by X-ray diffraction technique. Device behaviors of the fabricated devices are mainly analyzed in response to incident light. At this characterization step, electrical measurements are conducted in a dark environment and under different light intensities ranging from 20 to 100 mW/cm2. For instance, the Ppy-Silicene/pSi device exhibited a barrier height of 0.57 eV and an ideality factor of 3.1, compared to the Ppy-Silicene/n-Si device, which showed a barrier height of 0.55 eV and an ideality factor of 4.9. Characteristic photodiode parameters, such as light sensitivity, responsivity, and detectivity are obtained through current-voltage/time measurements depending on power of light. In addition to these parameters, performance-determining parameters for the diodes as barrier height, series resistance, and ideality factor are investigated according to thermionic emission and Cheung's approaches. The results indicate that the performance of the Ppy-Silicene/p-Si photodiode is significantly more effective than that of the photodiode produced with n-Si substrate. As a result of these experimental works, the fabricated Ppy-Silicene composite material and its diodes, especially on p-Si, can be evaluated as a promising candidate for optoelectronic technology.