High-Performance Perovskite Quantum Dot Solar Cells Enabled by Incorporation with Dimensionally Engineered Organic Semiconductor

Abstract

Perovskite quantum dots (PQDs) have been considered promising and effective photovoltaic absorber due to their superior optoelectronic properties and inherent material merits combining perovskites and QDs. However, they exhibit low moisture stability at room humidity (20–30%) owing to many surface defect sites generated by inefficient ligand exchange process. These surface traps must be re-passivated to improve both charge transport ability and moisture stability. To address this issue, PQD-organic semiconductor hybrid solar cells with suitable electrical properties and functional groups might dramatically improve the charge extraction and defect passivation. Conventional organic semiconductors are typically low-dimensional (1D and 2D) and prone to excessive self-aggregation, which limits chemical interaction with PQDs. In this work, we designed a new 3D star-shaped semiconducting material (Star-TrCN) to enhance the compatibility with PQDs. The robust bonding with Star-TrCN and PQDs is demonstrated by theoretical modeling and experimental validation. The Star-TrCN-PQD hybrid films show improved cubic-phase stability of CsPbI3-PQDs via reduced surface trap states and suppressed moisture penetration. As a result, the resultant devices not only achieve remarkable device stability over 1000 h at 20–30% relative humidity, but also boost power conversion efficiency up to 16.0% via forming a cascade energy band structure.

Phase transition engineering for effective defect passivation to achieve highly efficient and stable perovskite solar cells

“…This implies that the liquid phase transition can effectively reduce the Shockley–Read–Hall recombination. 74 Moreover, from the light-intensity-dependent J SC plots, the control and DOFo-treated PSCs exhibited the similar slope ( α ), which suggests that the predominant recombination process is trap-assisted recombination in the PSCs. 76 An in-depth analysis of the passivation effect on the charge transport non-radiative recombination at the interface was conducted through electrical impedance spectroscopy (EIS) measurement (Fig.…”

“…S14, ESI †) The AAFo-treated perovskite film exhibited an increased PL intensity and a slightly blue-shifted PL peak, attributed to the AAFo passivation. 74 In addition, the optoelectrical properties were evaluated by time-resolved photoluminescence (TRPL) analysis (Fig. 3a-d).…”

Efficient and stable hybrid conjugated polymer/perovskite quantum dot solar cells

“…In comparison with currently reported short ligands, conjugated polymers usually bear various functional side-groups that could efficiently passivate the defects, and the hydrophobic backbone would provide a physical barrier to prevent moisture from penetrating the QDs. 19,20 Hybrid polymer/metal chalcogenide-based QDs have been intensively investigated, but their efficiency is relatively low below 10%. [21][22][23] Considering the higher efficiency in CsPbI 3 QD solar cells, the hybrid polymer/CsPbI 3 QD strategy is promising for further enhancing the electronic coupling and stability.…”

Chirality Extends Multiple-Channel Bistable Responses in Hybrid Perovskites

“…have been proposed and validated to improve material properties during the exploration of materials. Among them, strategy of chiral induction has been widely applied in the research and design of multifunctional materials. − Chirality, a significant and fundamental attribute of Nature, has garnered widespread attention and tremendous interest for its potential applications in the fields of biology, chemistry, medicine, and materials science. − Incorporating it into materials can lead to the emergence of novel physical phenomena, such as optical activity, chiral magnetic effect, − and other charming physical properties. − For example, Bu’s group reported a couple of hybrid lead halide perovskites, ( d / l - Pro )­PbI 3 ·H 2 O, by incorporating chiral proline ( Pro ) . They achieved switchable optical properties of materials with large nonliner optics (NLO) coefficients, wide transparent regions, high laser damage thresholds, and high polarization ratios.…”