Blended PQT-12 and PC61BM Thin Films Based Self-Powered and Fast Response Photodetector

Abstract

This letter reports a p-type poly (3, 3”’- dialkylquaterthiophene) (PQT-12) and n-type [6, 6]-phenyl-C 61 -butyric acid methyl ester (PC61 BM) bulk-heterojunction (BHJ) based self-powered photodetector. When monochromatic light is incident on the device, our proposed device shows a self-powered photodetection property with a significant enhancement of current by nearly 1000 times at zero bias condition due to synergistic effect of PQT-12 and PC61 BM. The self-powered nature of the proposed device is shown by measuring its optical characteristics over a wide wavelength range of 300–800 nm under zero-bias condition. The maximum responsivity of ~167.5 mA/W, detectivity of $\sim {4}\times {10}^{{11}}$ cmHz $^{\text {1/2}}$ /W, and external quantum efficiency (EQE) of 41.6% are obtained at ~515 nm under an incident light intensity of $57~\mu \text{W}$ /cm2. The proposed BHJ photodetector gives a fast response with a rise time of ~70 ms and a fall time of ~100 ms.