High performance flexible organic photomultiplication photodetector based on an ultra-thin silver film transparent electrode

Abstract

Flexible and lightweight photomultiplication-type organic photodetectors (PM-OPDs) have attracted wide attention for their broad application prospects, especially in the field of wearable electronic products. However, the commonly used indium tin oxide (ITO) conductive anode is not conducive to realize high-performance flexible PM-OPDs due to its rigidity and fragility. Here, on the flexible polyethylene terephthalate (PET) substrate, we successfully fabricate highly sensitive poly 3-hexylthiophene:phenyl-C 70 -butyric acid methyl ester (P3HT:PC 70 BM, 100:1) based PM-OPDs using ultra-thin silver films as transparent anodes. Specifically, a 1 nm thick MoO 3 layer is utilized as the wetting layer for facilitating the silver film percolation, and a 2 nm thick MoO 3 layer, as the hole transport layer, is coated on top of the ultra-thin silver film before coating the P3HT:PC 70 BM film. The as-prepared flexible PM-OPDs based on the ultra-thin silver film exhibit the optimal external quantum efficiency (EQE) and responsivity (R) of 1.3 × 10 5 % and 388.4 A W −1 , respectively, under −15 V bias, which are 1.98 times and 2.15 times greater than those of the ITO anode based device. More importantly, the device has good flexibility with the EQE maintaining 70.6% of its initial value after bending 10 times, and 51.4% of its initial value after bending 1000 times. This work paves the way for developing flexible PM-OPDs as well as other flexible optoelectronic devices.

Recent Advances in Solution‐Processable Organic Photodetectors and Applications in Flexible Electronics

“…A flexible PM‐type OPD was demonstrated by replacing the glass/ITO substrate with a flexible PET/ZEOCOAT/MoO 3 (1 nm)Ag (9 nm)/MoO 3 (2 nm) substrate. [ 106 ] The flexible PM‐type OPD shows about two times higher responsivity and better flexibility over the rigid OPD. The device could maintain 51.4% of its initial EQE after bending 1000 times.…”

Dual‐Band Organic Photodetectors for Dual‐Channel Optical Communications

“…The dual-band OPDs have a −3dB cutoff frequency of > 100 kHz and a switching speed of over 1000 times per second between its NIR and visible light detection modes. In comparison with the traditional crystalline inorganic semiconductor-based PD technology, dual-band OPDs are an attractive option for next-generation large-area PDs, [28,29] due to their solution fabrication processes, [30,31] flexible design, [32][33][34] and adaptive manufacturability. [35][36][37]…”

Highly stabilized flexible transparent capacitive photodetector based on silver nanowire/graphene hybrid electrodes

“…In this regard, various flexible and conductive electrodes for photodetectors have been studied, such as carbon nanotubes (CNTs) 3 , graphene 4 – 8 , metal nanowires 9 , 10 , metal nanogrids 11 , 12 , and thin films 13 . Among these alternatives, one-dimensional (1D) metal networks, such as metal nanowires and metal fiber electrodes, have been extensively studied.…”