Interfacial‐Tunneling‐Effect‐Enhanced CsPbBr₃ Photodetectors Featuring High Detectivity and Stability

Abstract

Inorganic halide perovskite (HP)-based photodetectors (PDs) have exhibited fast response speed and high responsivity, but with low detectivity due to the high dark current of devices. Additionally, the intrinsic instability of HPs and interface deterioration originating from ion migration inhibit their practical applications severely. A tunneling organic layer is introduced to solve both these problems. Light-induced charge carriers can flow across the interfacial (poly(methyl methacrylate), PMMA) layer with appropriate thickness via the Fowler-Nordheim tunneling effect. Due to the effective control of dark current, the photo-/dark-current ratio reaches a giant value of 2.13 × 10 8 , and the peak detectivity is as high as 1.24 × 10 13 Jones. With such superiority, light signal as weak as 244 pW is accurately imaged by a PD array. Additionally, the hydrophobic organic layer inhibits the destruction of HPs caused by moisture and ion migration induced interface reaction, and negligible response attenuation is observed during continuous work in a humid environment for 48 h. This heterojunction structure design provides a new strategy to enhance the performance and stability of perovskite-based photoelectric and photovoltaic devices.

Ultrafast and Sensitive Self-Powered Photodetector Featuring Self-Limited Depletion Region and Fully Depleted Channel with van der Waals Contacts

“…Thus, it can be concluded that the photo-induced electrons will be transferred to Gr much faster, driven by the band bending of InSe nanosheet, and then recombine with holes through a non-radiative way (Figure S5c, Supporting Information). 22 These results verify a higher Fermi level of InSe than that of Gr and indicate a vdWs ohmic contact of Gr with InSe. In order to provide experimental demonstration of ohmic contact for Gr and InSe, the InSe device with two Gr electrodes was fabricated as shown in Figure S6 in the Supporting Information.…”

A Universal Method to Enhance Flexibility and Stability of Organic Solar Cells by Constructing Insulating Matrices in Active Layers

“…This suggests that the PAEF regions lead to the carrier accumulation at PM6/PAEF interface without forming traps in the blends, and the same phenomenon was also observed in halide perovskite photodetectors. [ 63 ] Fluorescences of the PM6/Y6 and the PM6/Y6/PAEF films are completely quenched, indicating that efficient charge transfer occurs between PM6 and Y6 with introducing PAEF insulating matrices. Then, we carried out incident light‐intensity ( P light ) dependent J – V characteristics to further reveal the charge recombination process, [ 64,65 ] and the data are summarized in Table 1 (details in Figures S28 and S29 in the Supporting Information).…”

“…It can be inferred that such materials as supporting matrices in the BHJ layers exhibit efficient tunneling effect at the interfaces, which is a common phenomenon in tunnel diode devices and interfacial materials (such as LiF and Ga 2 O 3 ) for photodiodes and perovskite solar cells. [ 63,71–77 ]…”

Enhanced hole injection assisted by electric dipoles for efficient perovskite light-emitting diodes

“…In modeling, Miller-Abrahams theory is adopted to study the field-dependent hole hopping process, which is an effective method to describe the carriers hopping 24,25 . According to this theory, the parameter of the averaged hopping frequency ω(F e ), which indicates the hole transporting rate from HIL to HTL, can be written as:…”