Flexible and efficient perovskite quantum dot solar cells via hybrid interfacial architecture

Abstract

All-inorganic CsPbI3 perovskite quantum dots (QDs) have received intense research interest for photovoltaic applications because of the recently demonstrated higher power conversion efficiency compared to solar cells using other QD materials. These QD devices also exhibit good mechanical stability amongst various thin-film photovoltaic technologies. In this work, through developing a hybrid interfacial architecture consisting of CsPbI3 QD/PCBM heterojunctions, we report the formation of an energy cascade for efficient charge transfer at both QD heterointerfaces and QD/electron transport layer interfaces. The champion CsPbI3 QD solar cell has a best power conversion efficiency of 15.1%, which is among the highest report to date. Building on this strategy, we demonstrate the very first perovskite QD flexible solar cell with a record efficiency of 12.3%. A detailed morphological characterization reveals that the perovskite QD film can better retain structure integrity than perovskite bulk thin-film under external mechanical stress. This work is the first to demonstrate higher mechanical endurance of QD film compared to bulk thin-film, and highlights the importance of further research on high‐performance and flexible optoelectronic devices using solution-processed QDs.

Ligand exchange engineering of FAPbI3 perovskite quantum dots for solar cells

“…Due to the combined advantages of perovskites and quantum dots (QDs), such as low cost, solution processability, tunable bandgap energy (E g ) and high stability [1][2][3][4][5][6][7][8][9], perovskite QDs (PQDs) have received increasing attention for application in light-emitting diodes [10,11], photodetector [12][13][14], and solar cells [15,16]. Since the first PQD solar cells (PQDSCs) were successfully fabricated by Swarnkar et al in 2016 [17], with the material synthesis improvement [18][19][20], post-treatment of PQDs [21][22][23][24][25], and tuning device structure of solar cells [26][27][28][29], the performance of inorganic CsPbI 3 PQDSCs has considerably improved. Compared with CsPbI 3 PQDs, formamidinium lead triiodide (FAPbI 3 ) PQDs present a more ideal bandgap (~ 1.5 eV) for achieving highly efficient PQDSCs [30], and show superiority in phase stability [31], which is crucial for the future commercial application of solar cells.…”

Inorganic Halide Perovskite Quantum Dots: A Versatile Nanomaterial Platform for Electronic Applications

“…Inorganic perovskite QDs have dimensions on the nanoscale, making them more adaptable to flexible applications than their bulk counterparts. Recently, highly flexible perovskite QD solar cells with excellent bending durability were reported [210], while a wide range of flexible electronics based on these emerging QDs clearly warrants future research efforts. In addition to the adaption of inorganic perovskite QDs for the substrate, the barrier materials for encapsulation and their mechanical durability, surface hydrophobicity, water vapor, and oxygen transmission rate are imperative for preventing perovskite from degrading [211].…”

Inhomogeneous light photovoltaic effect in neighboring quantum dots

“…To change the situation of high costs in first generation solar cells and low efficiency in second generation solar cells, a series of new material based solar cells are emerged, call third generation solar cells. Third generation solar cells do not rely on traditional p-n junctions, they are made from new developed sensitizing materials, such as dye molecules [11], QDs [12][13][14] and organic polymers [15]. These nano materials could help us to harvest light energy at low cost and low heat emission compared with the other two generation solar cells.…”

“…Actually, the third generation solar cells inherit some significant features of the first and second generation cells. For example, p-n type bilayer structure, integrability, thin film designs still play important role in recent research and development of nano material based solar cells [12][13][14][15][16][17][18][19][20][21][22]. Why p-type and n-type materials are important?…”