Impact of Varying Position and Ratio of Charge Generation Layer on Performance Parameters of Organic Photodiode

Abstract

Organic photodiodes have emerged as the best alternative to inorganic devices during the last decade. Herein, a highly efficient organic photodiode having charge generation layer (CGL) is demonstrated. This charge generation layer is a combination of HAT-CN (hexaazatriphenylene-hexacarbonitrile) and TAPC (1,1-bis[(di-4-tolyamino)phenyl)]cyclohexane) materials which generate electrons and holes, correspondingly. Moreover, in this work, the proposed device (D2) is compared with other four non-CGL (D1) and CGL based (D3, D4 and D5) devices. In all the CGL based devices, positional variation of the CGL layer is incorporated. In the proposed device (D2), the CGL is situated outside the active layer in such a manner like HAT-CN is placed near acceptor and TAPC is near donor layer. In this way, the proposed device is showing the remarkable improvements in terms of photocurrent and dark current as 134.2 nA and 10.2 nA, respectively. The value of photocurrent of D2 is 34 times increased of the reference device (D1). Furthermore, on comparing with other CGL based devices D3, D4 and D5, photocurrent of D2 is approx 1.6, 1.4 and 9 times enhanced, correspondingly. Moreover, the thickness optimization and internal analysis of the proposed device are also performed to show the novelty of the presented work.