Performance Improvement of Perovskite Solar Cells by Interactions between Nano‐Sized Quantum Dots and Perovskite

Abstract

Perovskite solar cells (PSCs) have undergone rapid progress and attracted considerable attention as a promising alternative to conventional photovoltaics but currently still face the challenges of Shockley-Queisser (SQ) limit and stability. Herein, the use of quantum dots (QDs) for the advancement of PSCs is focused on. The interactions between QDs and perovskite are discussed in terms of energy and charge transfer. The effective strategies for performance improvement of devices treated with QDs are interpreted from the point of view of surface modification (passivation and mixing), and microstructure (buffer function) and nanostructure (core/shell structure). In particular, possible routes to success in surpassing the SQ limit are summarized in association with the corresponding mechanisms. Also, the mechanisms for the enhancement of stability by QD treatment are analyzed, including quantum confinement effect, crystallization, ion migration inhibition, hydrophobicity improvement, passivation, and decomposition suppression. In addition, application of QDs to charge transporting layers is introduced and the resultant changes in device performance and stability are pointed out. The insights gained from this review are very crucial for the further advancement of PSCs treated with QDs.

The Electronic Properties of a 2D Ruddlesden‐Popper Perovskite and its Energy Level Alignment with a 3D Perovskite Enable Interfacial Energy Transfer

“…From both, the absorption and PL spectra of thick PEA 2 PbI 4 films, as shown in Figure S1 (Supporting Information), an optical transition at 2.36 eV is observed, which overlaps with the absorption of MAPbI 3 . Such spectral overlap between the PL of the PEA 2 PbI 4 and the absorption of the MAPbI 3 implies the possibility of Förster-type resonance energy transfer (FRET) across the interface, [60][61][62] and can result in the enhancement of the PL emission of MAPbI 3 . This is unambiguously inferred from Figure 4a, where a strong PL enhancement of MAPbI 3 is observed (centered at 1.60 eV) upon the addition of a PEA 2 PbI 4 when excited at 3.06 eV.…”

K+-doped P6̄ crystals of NIR-upconverting NaYF4:Yb3+/Ho3+ conform to the ‘strain–intensity’ relationship

“…20,48 Rationalized such phenomenon in terms of the partial restoration of local symmetry due to some kind of secondary reordering or restructuring around the activator ions due to the overpopulation of non-lanthanides dopant ion. 5…”

“…20,48 Rationalized such phenomenon in terms of the partial restoration of local symmetry due to some kind of secondary reordering or restructuring around the activator ions due to the overpopulation of nonlanthanides dopant ion. 5 In a recent report on Li + -doped Gd 2 O 3 crystal systems, at a significantly higher Li + mol%, the corresponding lattice strain was shown to be correlated with the extent of local disorder, which was connected with the ion pair distances of the host material. 58 Similarly, as we detected the possible presence of local disorder from the EXAFS study (Table S1 †) and the indication of changes in the Y-F bond distances (Fig.…”

“…For instance, the management of internal and external strain through lattice engineering has successfully addressed the performance enhancement issue in different types of perovskite-based solar cells. [1][2][3][4][5][6] Lattice strain and disordering has been believed to affect carrier diffusion while playing a central role in regulating the charge recombination process. [7][8][9][10] Lattice strain has been reported to control carrier relaxation dynamics, spectroscopy, and photoluminescence by manipulating the number of trap states in different types of quantum dots.…”

Quantum Dots, Passivation Layer and Cocatalysts for Enhanced Photoelectrochemical Hydrogen Production

“…[21] The third is increased electron-hole pairs by multiple exciton generation (MEG) for improving power conversion efficiency by overcoming the restriction that single photons can only trigger one electron-hole pair. [22] The last is the large extinction coefficient for improved adsorption. [23] However, most of the QDs have low PEC stability because holes induce anodic corrosion.…”