One‐Source Strategy Boosting Dopant‐Free Hole Transporting Layers for Highly Efficient and Stable CsPbI₂Br Perovskite Solar Cells

Abstract

All-inorganic perovskites have emerged as promising photovoltaic materials due to their superior thermal stability compared to their organic-inorganic hybrid counterparts. However, the inferior film quality and doped hole transport layer (HTL) have a strong tendency to degrade the perovskite under high temperatures or harsh operating conditions. To solve these problems, a one-source strategy using the same polymer donor material (PDM) to simultaneously dope CsPbI 2 Br perovskite films via antisolvent engineering and fabricating the HTL is proposed. The doping assists perovskite film growth and forms a top-down gradient distribution, generating CsPbI 2 Br with enlarged grain size and reduced defect density. The PDM as the HTL suppresses the energy barrier and forms favorable electrical contacts for hole extraction, and assemble into a fingerprint-like morphology that improves the conductivity, facilitating the creation of a dopant-free HTL. Based on this onesource strategy using PBDB-T as PDM, the CsPbI 2 Br perovskite solar cell with a dopant-free HTL achieves a power conversion efficiency (PCE) of 16.40%, which is one of the highest PCEs reported among all-inorganic CsPbI 2 Br pero-SCs with a dopant-free HTL. Importantly, the devices exhibit the highest thermal stability at 85 °C and operational stability under continuous illumination even with Ag as the top electrode and present good universality.

Chromium‐Based Metal–Organic Framework as A‐Site Cation in CsPbI2Br Perovskite Solar Cells

“…[1][2][3][4][5] However, this replacement also reduces the tolerance factor (≈0.8), jeopardizing the perovskite structural stability at room temperature. [6][7][8] In the presence of water or We designed and grew Cr-MOF-based perovskite single crystals by a simple hydrothermal approach based on the stoichiometric mixing of PbI 2 with 2,2′:6′,2″-terpyridine hydriodic acid salt (TPy•2HI) and the posterior reaction of the obtained product with chromium acetate (see details in the Supporting Information). The intermediate single crystal and the final Cr-MOF single crystal were structurally resolved and refined by SHELXT and OLEX2 softwares (Figure 1a and Figure S1, Supporting Information).…”

Application of intrinsically conducting polymers in flexible electronics

“…PSCs have received great attention since its discovery in 2011 because of their high photovoltaic efficiency 93–95 . They have a similar architecture to OSCs with the active layer sandwiched between two electrodes.…”

All‐Inorganic CsPbI2Br Perovskite Solar Cells: Recent Developments and Challenges

“…The doped HTL and low‐quality films have greater tendency to disintegrate the perovskite under a severe operating environment or at high temperatures. To address this issue, Li et al [ 179 ] developed a single‐source technique utilizing the polymer donor material (PDM) for doping the CsPbI 2 Br films. The PDM HTL generates advantageous electrical contacts for hole extraction, lowers the energy barrier, and assembles into a fingerprint‐like morphology that increases conductivity, allowing for the construction of a dopant‐free HTL.…”