Improved Electrical and Structural Stability in HTL-Free Perovskite Solar Cells by Vacuum Curing Treatment

Abstract

Device engineering with proper material integration into perovskite solar cells (PSCs) would extend their durability provided a special care is spent to retain interface integrity during use. In this paper, we propose a method to preserve the perovskite (PSK) surface from solvent-mediated modification and damage that can occur during the deposition of a top contact and furtherly during operation. Our scheme used a hole transporting layer-free top-contact made of Carbon (mostly graphite) to the side of hole extraction. We demonstrated that the PSK/graphite interface benefits from applying a vacuum-curing step after contact deposition that allowed mitigating the loss in efficiency of the solar devices, as well as a full recovery of the electrical performances after device storage in dry nitrogen and dark conditions. The device durability compared to reference devices was tested over 90 days. Conductive atomic force microscopy (CAFM) disclosed an improved surface capability to hole exchange under the graphite contact after vacuum curing treatment.

Black‐Yellow Bandgap Trade‐Off During Thermal Stability Tests in Low‐Temperature Eu‐Doped CsPbI3

“…To achieve this goal, some issues like the intrinsic instability of the perovskite material, especially when it is exposed to humidity and elevated temperatures, have to be fully solved. [ 5–13 ]…”

“…To achieve this goal, some issues like the intrinsic instability of the perovskite material, especially when it is exposed to humidity and elevated temperatures, have to be fully solved. [5][6][7][8][9][10][11][12][13] Recently, besides the most studied hybrid organic/inorganic perovskites (methylammonium lead iodide (MAPbI 3 ), [14] formamidinium lead iodide (FAPbI 3 ), and methylammonium MA-FA mixed perovskite), the all-inorganic Cs-based perovskites [15] like CsPbI 3 have received much attention because of their greater thermal stability. Moreover, CsPbI 3 perovskites with energy gap (E gap %1.73 eV) are promising candidates for Si/PSK monolithic tandem solar cells.…”

Insights into the Development of Monolithic Perovskite/Silicon Tandem Solar Cells

“…Although 2T PK/c-Si tandem have produced remarkable energy conversion efficiencies, their underperforming durability is a key challenge to the commercial viability of this technology. [157][158][159] So far, a lot of work has been done on the instability of perovskite materials and single-junction perovskite devices, however, little attention has been paid to 2T PK/c-Si tandem. [160][161][162] Even there are some studies concentrated on the stability issues, most of them have only focused on one or two of these influencing factors.…”

Perovskite solar cells from the viewpoint of innovation and sustainability

“…Another approach to prevent solvent-mediated interfacial degradation consists of applying a vacuum-curing after DB (DBv-PSCs). 60 In the treatment, a pressure of 10 −2 mbar for 24 h on the devices is applied. DBv-PSCs, compared to the hot-press transfer method, provide a better guarantee of the carbon electrode adhesion to the underlying PSK through the whole contact area and indeed they are technologically more reliable for performance recovery after use.…”