A comprehensive investigation of the structural (SEM), electrical, optoelectronic, and photonic behaviors of BCZVB-Based organic semiconductor photodetectors

In this thesis, the fabrication and photonic characterization of optoelectronic devices based on polymeric organic semiconductors and magnetic nanocomposite structures were systematically investigated. Within the scope of the study, Schottky-type photodetector devices with an Al/BCzVB/n-Si architecture were successfully fabricated using BCzVB as the active layer. The electrical, optical, and optoelectronic properties of the fabricated devices were evaluated through current–voltage (I–V) measurements, UV–Vis absorption analysis, time-dependent photoresponse measurements, and performance tests under various illumination intensities. I–V characteristics obtained under dark and illuminated conditions revealed a pronounced rectifying behavior and a significant increase in current upon illumination, confirming effective photocarrier generation. Key photodetector parameters, including photocurrent (Iph), photosensitivity (K), responsivity (R), and specific detectivity (D*), were calculated and found to increase systematically with increasing light intensity. The high responsivity and detectivity values obtained at elevated illumination levels indicate low noise characteristics and a strong signal-to-noise ratio of the device. Furthermore, time-resolved light on–off measurements demonstrated fast response times and excellent photoresponse stability, highlighting the reliability and reproducibility of the photodetection behavior. Overall, the experimental results demonstrate that the Al/BCzVB/n-Si photodetectors are promising candidates for high-performance optoelectronic sensing applications, offering stable operation over a wide spectral range at low operating voltages.