Impact of implementation of copper phthalocyanine as a second donor on the photosensitive structure characteristic with bulk heterjunction based on PCDTBT and PC$_{61}$BM

The paper presents the process of creating and studying photosensitive structures based on an organic acceptor [6,6]-methyl ester of phenyl-C$_{61}$-butyric acid (PC$_{61}$BM) and donors of poly[N-9"-hepta-decanyl-2,7-car-basol-alt-5,5-(4',7'-di-2-tienil-2',1',3'-benzothiadiazole)] (PCDTBT) and copper phthalocyanine (CuPc). Photosensitive structures of the FTO/PCDTBT:PC$_{61}$BM/InGaSn type were obtained, the spectral response of which lies in the range from 450 to 750 nm, and FTO/PCDTBT:CuPc:PC$_{61}$BM/InGaSn for which, with the introduction of an additional donor, it was possible to widen the spectral response to the range from 400 to 850 nm. An assumption was made about the formation of additional energy levels in the structure and non-direct transitions between organic donors, as a result of which the spectral response is broadened in both the short-wave and long-wave spectral regions. It was also possible to increase the maximum sensitivity of the structure by almost 3 times from 72 mA/W to 210 mA/W as a result of increasing the number of effective ways of transferring charge carriers to contacts and reducing the energy of potential barriers in the structure. The addition of an additional donor to the structure led to an increase in the currents of the reverse and forward branches of the VAC, a decrease in the level of its own noise and an increase in the short-circuit current. The FTO/PCDTBT:CuPc:PC$_{61}$BM/InGaSn structure created in the work has a high potential for creating highly efficient photodetectors of the visible and near infrared ranges.