High speed responsive near infrared photodetector focusing on 808 nm radiation using hexadecafluoro-copper-phthalocyanine as the acceptor

We have demonstrated an organic photodetector (PD) which can detect 808 nm radiation in near infrared (NIR) region. The photodiode has a hybrid planar-mixed heterojunction structure: ITO/CuPc (10 nm)/CuPc:F16CuPc (1: 2, 30 nm)/F16CuPc (20 nm)/LiF (1 nm)/Al. Here, CuPc and F16CuPc denote copper-phthalocyanine and hexadecafluoro-copper-phthalo-cyanine complexes, respectively. The photodiode behaves a response time of 80 ns and a bandwidth of 14 MHz, which are higher than those of recent reports. At the same time, the response waveband of the photodiode covers longer wavelength in NIR comparing to the PD reported. It is conjectured that the high detection performance is due to high electron-mobility of F16CuPc, the large band edge offset between D/A molecules as well reasonable design of the diode structure. The detail working mechanism is also augured. (C) 2010 Elsevier B. V. All rights reserved.