All‐Sprayed‐Processable, Large‐Area, and Flexible Perovskite/MXene‐Based Photodetector Arrays for Photocommunication

Abstract

Flexible photodetectors (PDs) are attracting more attention due to their promising applications in wearable optoelectronic devices, bendable imaging sensors, and implantable optoelectronics. For the easy‐processable technology of massively fabricating PDs, instead of the expensive and complex high‐vacuum technique, the well‐matched work function of their active materials is essential. Herein, all‐sprayed‐processable and large‐area PDs are demonstrated on common paper based on two‐dimensional (2D) CsPbBr3 nanosheets and conductive Ti3C2Tx (MXene). Ascribed to the superior conductivity of MXene, high crystallinity of 2D CsPbBr3, and their well‐matched work function, the as‐prepared PDs exhibit an outstanding on/off current ratio up to 2.3 × 103 and a remarkable photoresponse as fast as 18 ms. Specifically, the detectivity (D*) of 6.4 × 108 Jones and responsivity (R) of 44.9 mA W−1 under a bias of 10 V are achieved. Besides, after bending 1500 cycles, the as‐prepared PDs can still maintain the excellent flexibility and stability. Based on this, a superior‐quality and large‐area 1665 pixel sensor in 72 cm2 (≈24 units cm−2) is developed, and it can clearly transmit the image of “0” to realize the photocommunication function. This work provides a low‐cost method of massively producing the flexible large‐area PDs for wearable optoelectronic devices and expanded photocommunication.

Titanium-carbide MXenes for work function and interface engineering in perovskite solar cells

“…In general, the reported UPS measured WF values for Ti3C2Tx MXene range from 3.4 eV 41 to 4.62 eV. 42 Such large modulation of the WF could be attributed to the different etching environment dramatically affecting the surface termination. The WF value of synthesized MXene is in agreement with the XPS results and should be due to the substantial percentage of hydroxyl groups terminating the Ti3C2Tx matrix.…”

Porous perovskite films integrated with Au–Pt nanowire-based electrodes for highly flexible large-area photodetectors

“…2g. The maximum value of R and D* for 1 wt % PS-MAPbI 3 device is 2.73 A W −1 and 6.2 × 10 13 Jones at illumination intensity of 0.001 mW cm −2 , which is comparable and even higher than the previous reports on the flexible photodetectors (Table 1) 3,12,13,20,[27][28][29][30][31][32][33][34][35][36][37][38] . In contrast, the plain MAPbI 3 device achieves only R (0.61 A W −1 ) and D* (0.86 × 10 13 Jones), which implies that the incorporation of 1 wt % PS in MAPbI 3 greatly improved the photodetector performance.…”

Flexible Sensors—From Materials to Applications

“…Perovskites can be divided into organic-inorganic halide perovskites following the structure ABX 3 (Figure 7a), where A is an organic cation, B is a metal cation and X is an halide anion, or inorganic only halides [272,273]. In flexible sensors, these materials have been mostly employed as active materials in photodetectors, prevalently in the form of organic-inorganic methilammonium lead bromide/iodide/chloride (CH 3 NH 3 PbX or MAPbX) [18,29,272,[274][275][276][277][278][279][280][281], and inorganic caesium lead bromide (CsPbBr 3 ) [282][283][284][285], or as piezoelectric materials such as PbZr x Ti 1-x O 3 (PZT) on ultrasound sensors [286]. The application and development of these materials for flexible optoelectronic applications has been widely researched due to their optical and electrical properties.…”