Exploring Low-Frequency Noise Behavior in Vertically Structured Organic Schottky Photodiodes

This study delves into low-frequency noise behavior in organic photodiodes (OPD) using DPPT-TT, a prominent organic polymer. Utilizing the 9812D lowfrequency noise test platform, we systematically examined noise patterns at varying voltage levels. The investigation integrates the Hooge low-frequency noise analysis model to elucidate the nature of noise types, carrier transport mechanisms, and generation-recombination (g-r) noise phenomena, especially under high-voltage conditions. Key findings reveal a transition in noise behavior: at bias voltages below 0.9V, the noise predominantly resembles 1/f noise. However, a distinct shift to g-r noise characteristics is observed above this threshold, attributed to increased band bending and the consequent proximity of defect energy levels to the Fermi level under high bias voltages. These insights offer a crucial theoretical framework for understanding the noise characteristics in DPPT-TT organic semiconductors and pave the way for exploring the transport mechanisms in various devices based on this material.