Perovskite Quantum Dots in Solar Cells

Abstract

Perovskite quantum dots (PQDs) have captured a host of researchers' attention due to their unique properties, which have been introduced to lots of optoelectronics areas, such as light-emitting diodes, lasers, photodetectors, and solar cells. Herein, the authors aim at reviewing the achievements of PQDs applied to solar cells in recent years. The engineering concerning surface ligands, additives, and hybrid composition for PQDSCs is outlined first, followed by analyzing the reasons of undesired performance of PQDSCs. Subsequently, a novel overview that PQDs are utilized to improve the photovoltaic performance of various kinds of solar cells, is provided. Finally, this review is summarized and some challenges and perspectives concerning PQDs are also discussed.

Structural engineering of single-crystal-like perovskite nanocrystals for ultrasensitive photodetector applications

“…12 Perovskite QDs possess several advantages over polycrystalline thin films, some of which include widely tunable bandgap energy, efficient photoluminescent quantum yield, and low charge recombination at grain boundaries. 13 In addition, one of the advantages of perovskite QDs is their wide adaptability to solution processing without complex post-treatments after QDs have been synthesized. QDs, however, are limited in size to a few tens of nanometers, which can lead to shorter charge transport lengths than crystalline thin films.…”

Limits of Defect Tolerance in Perovskite Nanocrystals: Effect of Local Electrostatic Potential on Trap States

“…As a result of their high photoluminescence quantum yield, facile synthesis, narrow emission width, and tunable bandgap across the visible spectrum depending on the halide composition, , lead halide perovskite nanocrystals (NCs) are of great interest for application in devices. − For instance, they can be used as a color-converting phosphor, , lasing material, − absorber layer in solar cells, − and emitter in light-emitting diodes. ,, The high performance of lead halide perovskite-based materials is often linked to their defect tolerance, which is attributed to a combination of the high formation energy of defects , and the electronic structure of the conduction (CB) and valence bands (VB). ,, The latter point is illustrated in Figure , where the electronic structure of perovskites is compared with that of common “defect-intolerant” semiconductors, which include II–VI (e.g., CdSe) and III–V (e.g., InP) materials. Taking CdSe as an example, as shown in Figure , the bandgap is formed between bonding states (the VB) and antibonding states (the CB).…”

Molecular design for perovskite solar cells

“…The halide perovskite precursor solutions are rich in tunable organic molecules, including the precursors, the additives, and the solvent molecules; these are all closely related to the coordination chemistry of the functional molecules and strongly affect the resulting perovskite film quality. Many efforts have been devoted to modifying the precursor solution, additives, and solvents, such as on those for FAPbI 3 preparation, 56‐58 additive MACl, 59‐62 ionic liquid, 63‐65 and MAPbBr 3 quantum dots 66‐68 . For example, the AX and BX 2 precursors in the precursor solution are essentially in the molecular form at the starting point, and non‐stoichiometric precursors are viable to generate improved perovskite film quality; the unreacted PbI 2 is suggested to improve the perovskite film crystallinity 69‐71 and facilitate the electron transfer to the neighboring TiO 2 layer.…”