Correlating Charge‐Carrier Dynamics with Efficiency in Quantum‐Dot Solar Cells: Can Excitonics Lead to Highly Efficient Devices?

Abstract

The photovoltaic performance of quantum-dot solar cells strongly depends on the charge-carrier relaxation and recombination processes, which need to be modulated in a favorable way to obtain maximum efficiency. Recently, significant efforts have been devoted to investigate the carrier dynamics of nanocrystal sensitizers, both in solution and deposited on TiO photoanodes, with the aim to correlate the excitonics with solar-energy conversion efficiency. This Minireview summarizes some proof of the concepts that efficiency can be directly correlated to the exciton dynamics of quantum-dot solar cells. The presented findings are based on CdSeS alloy, CdSe/CdS core/shell, Au/CdSe nanohybrids, and Mn-doped CdZnSSe nanocrystals, where the favourable excitonic processes are optimized to enhance the efficiency. Future prospects and limitations are addressed as well.

Experimental and Theoretical Study into Interface Structure and Band Alignment of the Cu2Zn1–xCdxSnS4 Heterointerface for Photovoltaic Applications

“…The performance of polycrystalline PV cells can be significantly influenced by charge carrier dynamics and grain boundary engineering, − hence their deep understanding in Cu-based quaternary chalcogenides will assist future optimization of PV devices to achieve improved performance. In earlier investigations, − we have reported a direct correlation between efficiency and carrier dynamics in solar cells. Solar device performance can be significantly enhanced with elongated charge-carrier lifetimes when the grain size is increased from a few hundred nanometers to the micrometer level .…”

Ultrafast Charge Delocalization Dynamics of Ambient Stable CsPbBr3 Nanocrystals Encapsulated in Polystyrene Fiber

“…It is noteworthy here that the efficiency of optoelectronic devices is mainly based on carrier dynamics including large carrier mobility, higher charge separation at interfaces, and slower charge recombination processes [23] . In solar cells, slow cooling provides an opportunity to extract the charge carriers before they give off their excessive energy as heat, resulting in achievement of the corresponding higher open circuit voltage [24] . To increase the device performance, the carrier dynamics should be clearly addressed, particularly if the NCs are embedded in a polymer environment.…”

Quantum Dot Solar Cells: Small Beginnings Have Large Impacts

“…We start with a brief overview of the processes that occur at each time scale ranging from a few femtoseconds to microseconds before giving an in-depth discussion of the progress of Pb-based QD solar cells (QDSCs). For in-depth discussions on each subtopic, we refer the interested readers to more specific reviews [27][28][29][30][31][32][33][34][35][36][37][38][39][40][41].…”