Broadband organic photodetectors based on ternary blend active layers with enhanced and spectrally flat response. Issue 40 (30th September 2020)

• Record Type: Journal Article
• Authors: Wang, Jianbin; Chen, Shan-Ci; Yin, Zhigang; Zheng, Qingdong
• Is Part Of: Journal of materials chemistry. Volume 8:Issue 40(2020)
• Page Start: 14049
• Page End: 14055
• Publication Date: 2020-09-30
• Subjects: Materials -- Periodicals; Chemistry, Analytic -- Periodicals; Optical materials -- Research -- Periodicals; Electronics -- Materials -- Research -- Periodicals; 543.0284
• DOI: 10.1039/d0tc02708a
• Languages: English
• ISSNs: 2050-7526

Abstract

Abstract : Under −25 V bias, the optimized ternary OPD exhibits a relatively flat EQE spectrum from 330 to 810 nm with an average EQE of 3.3 × 10 5 % which is more than 40 times larger than that of the binary OPD. Abstract : It is greatly in demand but still challenging to achieve organic photodetectors (OPDs) having both spectrally flat response from ultraviolet to near-infrared and high external quantum efficiencies (EQEs). Herein, ternary photomultiplication (PM)-type OPDs are fabricated with two donors and one acceptor in the bulk-heterojunction (BHJ) active layers. Under −25 V bias, the optimized ternary OPD exhibits a relatively flat EQE spectrum from 330 to 810 nm with an average EQE of 3.3 × 10 5 % which is more than 40 times larger than that of the binary OPD. In particular, an EQE up to 5.1 × 10 5 % at 380 nm is obtained for the ternary OPD, representing a record high value among all reported OPDs to the best of our knowledge. Compared to the binary OPD under −25 V bias and 380 nm light illumination, the linear response range of the ternary OPD under the same conditions is 4.5 times larger. Moreover, the ternary OPD shows a rise time of ∼42 ms which is more than one-fold faster than the binary OPD under the same conditions. Therefore, a ternary BHJ provides an effective strategy to develop broadband OPDs with improved EQEs, extended linear response range, faster response, and spectrally flat response from the ultraviolet to the near-infrared region.