Electron Transport Mechanisms in Perovskite Solar Cells

Perovskite solar cells harness light-induced charge carriers within a hybrid organic–inorganic lattice, where efficient electron transport underpins record-breaking power conversion efficiencies. Upon photon absorption, excitons rapidly dissociate into free electrons and holes; electrons are then selectively shuttled towards a designated electron transport layer (ETL) while holes migrate to the counter electrode. The choice of ETL material—commonly metal oxides such as titanium dioxide or tin oxide—determines conduction band alignment, carrier mobility and interfacial recombination rates. Strategies to improve electron extraction include chemical doping, surface passivation and energy‐level tuning, all aimed at minimising trap‐state density and hysteretic current–voltage responses. Interfacial engineering by means of low‐temperature deposition, additive incorporation or nanoparticle modification promotes uniform film formation, suppresses non‐radiative recombination and enhances device stability. Advanced characterisation has revealed that cation or anion dopants not only shift energy levels to optimise band offsets but also mitigate oxygen vacancies and under-coordinated sites. Collectively, these approaches enable perovskite devices to approach theoretical performance limits, while opening pathways to flexible, large‐area and low-cost photovoltaics with operational lifetimes exceeding industry benchmarks.

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Electron Transport Mechanisms in Perovskite Solar Cells publication trend

The graph below shows the total number of articles in electron transport mechanisms in perovskite solar cells across all publications each year (not limited to Nature Index journals).

Technical terms

Electron transport layer (ETL): A semiconductor interface layer that selectively conducts electrons while blocking holes, critical for efficient charge extraction.

Band alignment: The relative positioning of conduction and valence bands at material interfaces, determining charge‐transfer efficiency.

Trap states: Defect‐related energy levels within the bandgap that capture charge carriers and promote non‐radiative recombination.

Interfacial passivation: Chemical or structural modification of an interface to neutralise defects and reduce recombination losses.

Hysteresis: A lag in current response when voltage is swept, often caused by ion migration or interfacial traps in perovskite devices.

References

1. Nitrogen‐doped tin oxide electron transport layer for stable perovskite solar cells with efficiency over 23%. Interdisciplinary Materials (2022).
2. Up-Scalable Fabrication of SnO2 with Multifunctional Interface for High Performance Perovskite Solar Modules. Nano-Micro Letters (2021).
3. Efficient electron extraction of SnO2 electron transport layer for lead halide perovskite solar cell. npj Computational Materials (2020).