A route to high gain photodetectors through suppressed recombination in disordered films

Abstract

High response organic ultraviolet photodetector based on blend of 4 , 4 ′ , 4 ″ -tri-(2-methylphenyl phenylamino) triphenylaine and tris-(8-hydroxyquinoline) gallium Appl. Phys. Lett. 93, 103309 (2008); 10.1063/1.2980025High gain, broadband In Ga As ∕ In Ga As P quantum well infrared photodetector Appl. Phys. Lett. 89, 081128 (2006); 10.1063/1.2338803Low-frequency noise gain and photocurrent gain in quantum well infrared photodetectors Secondary photocurrents offer an alternative mechanism to photomultiplier tubes and avalanche diodes for making high gain photodetectors that are able to operate even at extremely low light conditions. While in the past secondary currents were studied mainly in ordered crystalline semiconductors, disordered systems offer some key advantages such as a potentially lower leakage current and typically longer photocarrier lifetimes due to trapping. In this work, we use numerical simulations to identify the critical device and material parameters required to achieve high photocurrent and gain in steady state. We find that imbalanced mobilities and suppressed, non-Langevin-type charge carrier recombination will produce the highest gain. A low light intensity, strong electric field, and a large single carrier space charge limited current are also beneficial for reaching high gains. These results would be useful for practical photodetector fabrication when aiming to maximize the gain. Published by AIP Publishing.

Photocurrent conversion capability of a 2D WS2-polyvinyl alcohol matrix and its DFT-based charge carrier dynamics analysis

“…The narrowband detector requirement is a further invention that uses ineffective charge transport to produce a sizable peak in external quantum efficiency near the optical absorption edge of active layers. 51 Different material-based photodetector devices are presented in Table 2 for the comparison of these results. The linear Ohmic properties are shown in Fig.…”