Performance Enhancement of Hole Transport Layer-Free Carbon-Based CsPbIBr[sub.2] Solar Cells through the Application of Perovskite Quantum Dots

• Published in: Nanomaterials (Basel, Switzerland) Switzerland), 2024-10, Vol.14 (20)
• Main Authors: Yu, Qi, Sun, Wentian, Tang, Shu
• Format: Article
• Language: English
• Subjects: Identification and classification; Perovskite; Properties; Quantum dots; Solar batteries; Solar cells; Structure
• ISSN: 2079-4991; 2079-4991
• DOI: 10.3390/nano14201651

CsPbIBr[sub.2] , with its suitable bandgap, shows great potential as the top cell in tandem solar cells. Nonetheless, its further development is hindered by a high defect density, severe carrier recombination, and poor stability. In this study, CsPbI[sub.1.5] Br[sub.1.5] quantum dots were utilized as an additive in the ethyl acetate anti-solvent, while a layer of CsPbBr[sub.3] QDs was introduced between the ETL and the CsPbIBr[sub.2] light-harvester film. The combined effect of these two QDs enhanced the nucleation, crystallization, and growth of CsPbIBr[sub.2] perovskite, yielding high-quality films characterized by an enlarged crystal size, reduced grain boundaries, and smooth surfaces. And a wider absorption range and better energy band alignment were achieved owing to the nano-size effect of QDs. These improvements led to a decreased defect density and the suppression of non-radiative recombination. Additionally, the presence of long-chain organic molecules in the QD solution promoted the formation of a hydrophobic surface, significantly enhancing the long-term stability of CsPbIBr[sub.2] PSCs. Consequently, the devices achieved a PCE of 9.20% and maintained an initial efficiency of 85% after 60 days of storage in air. Thus, this strategy proves to be an effective approach for the preparation of efficient and stable CsPbIBr[sub.2] PSCs.