TY - JOUR
T1 - Visible-blind near-infrared organic photodetectors
AU - Wang, Zhuangmiao
AU - Tang, Yu
AU - Han, Jiayin
AU - Zhu, Furong
N1 - Funding information:
This work was financially supported by the Research Grants Council, Hong Kong Special Administrative Region, China (12303920 and 12302623), the Guangdong-Hong Kong Technology Cooperation Funding Scheme GHP/121/21GD, the SZ-HK-Macau Science and Technology Plan Project (SGDX20201103095400005), and the Guangdong Basic and Applied Basic Research Fund GDSTC (2022A1515010020).
PY - 2024/1/8
Y1 - 2024/1/8
N2 - The presently available commercial photodetectors have a broadband photoresponse and require different external optical filters to block the undesired light outside the detection spectrum window, e.g., near-infrared (NIR) detection. The use of an NIR bandpass has technical limitations in curved or flexible large-area photodetectors, as an NIR bandpass depends critically on the difference in the interference of the optical path in the filter. This work reports the effort to develop a high-performance filter-free organic photodetector (OPD) with a double bulk heterojunction (BHJ) structure. The visible-blind NIR photodetection is realized by eliminating the photocurrent generated in the front visible light-absorbing BHJ optical depletion layer, due to the suppression of electron transport by incorporating a copper thiocyanate-based electron-blocking layer in the OPD. Only excitons generated in the rear NIR-absorbing BHJ contribute to photocurrent in the OPD, thereby achieving visible-blind NIR photodetection. The double BHJ OPD has a high responsivity of 0.38 A/W at 1050 nm and a specific detectivity of >1013 Jones over the wavelength range from 800 to 1050 nm, making it an ideal candidate for applications in optical communication, food quality detection, wellness monitoring, and NIR image sensors.
AB - The presently available commercial photodetectors have a broadband photoresponse and require different external optical filters to block the undesired light outside the detection spectrum window, e.g., near-infrared (NIR) detection. The use of an NIR bandpass has technical limitations in curved or flexible large-area photodetectors, as an NIR bandpass depends critically on the difference in the interference of the optical path in the filter. This work reports the effort to develop a high-performance filter-free organic photodetector (OPD) with a double bulk heterojunction (BHJ) structure. The visible-blind NIR photodetection is realized by eliminating the photocurrent generated in the front visible light-absorbing BHJ optical depletion layer, due to the suppression of electron transport by incorporating a copper thiocyanate-based electron-blocking layer in the OPD. Only excitons generated in the rear NIR-absorbing BHJ contribute to photocurrent in the OPD, thereby achieving visible-blind NIR photodetection. The double BHJ OPD has a high responsivity of 0.38 A/W at 1050 nm and a specific detectivity of >1013 Jones over the wavelength range from 800 to 1050 nm, making it an ideal candidate for applications in optical communication, food quality detection, wellness monitoring, and NIR image sensors.
UR - http://www.scopus.com/inward/record.url?scp=85181984632&partnerID=8YFLogxK
U2 - 10.1063/5.0180711
DO - 10.1063/5.0180711
M3 - Journal article
SN - 0003-6951
VL - 124
JO - Applied Physics Letters
JF - Applied Physics Letters
IS - 2
M1 - 021103
ER -