Perovskite Solar Cells on the Way to Their Radiative Efficiency Limit – Insights Into a Success Story of High Open‐Circuit Voltage and Low Recombination

Abstract

the first years, which I denote as 1 st generation perovskite solar cells, were limited by heterogeneous, rough and non-conformal films or particles (partly in classical dyesensitized solar cell architecture), [1,4,9,10] state-of-the art devices (referred to as 2 nd generation) comprise very compact, smooth films. [8,[11][12][13][14][15] The efficiency of state-of-the-art 2 nd generation devices, which is about 20%, can still be slightly improved by following the present trajectory of fine tuning the perovskite itself and its interfaces to charge transport layers.In this progress report I elucidate the outstanding material properties that rendered the perovskite success story possible, trying to shed some light on the processes determining V oc . After a brief introduction into the thermodynamics defining the theoretical, so-called radiative, efficiency limit of any solar cell, I will address the progress made on understanding and avoiding recombination processes in perovskite that reduce V oc below its radiative limit. I will comment on suitable characterization methods to quantify and identify recombination rates and mechanisms. Finally, I attempt to draw a roadmap on how far the efficiency of perovskite solar cells can go and what design principles are to be pursued to reach a 3 rd generation of highly efficient photovoltaic and other optoelectronic devices.

Two‐Terminal Perovskites Tandem Solar Cells: Recent Advances and Perspectives

“…Based on Vos's modeling, the optimal bandgaps were calculated to be 1.9 eV/1.0 eV for a two‐gap tandem cell, in which a maximum efficiency can reach 42% under standard light intensity (1 sun). Due to the strong optical absorption, long diffusion length distinguished compatibility, and tunability of broad bandgap, metal halide perovskites (ABX 3 ) have achieved rapidly increasing efficiencies and opened up a great potential to develop perovskite‐based tandem cells . Moreover, by taking advantages of cost‐effectiveness and facile solution processability, scalable processing methods for fabricating defect‐free and large‐scale perovskite films, such as antisolvent spraying, meniscus‐assisted solution printing (MASP), etc., further promote the development of perovskite‐based tandem cells.…”

Exploring Red, Green, and Blue Light‐Activated Degradation of Perovskite Films and Solar Cells for Near Space Applications

“…Hybrid organic–inorganic perovskites have emerged as a class of remarkable optoelectronic materials due to large absorption coefficients, long carrier diffusion length, and broad wavelength tunability . These excellent properties enable them to be suitable for application in solar cells, light‐emitting diodes, transistors, and lasers .…”

Planar Perovskite Solar Cells with High Open‐Circuit Voltage Containing a Supramolecular Iron Complex as Hole Transport Material Dopant

“…The outstanding photovoltaic performance of PSCs originates from the excellent photophysical and chemical properties of these perovskites, which exhibit tunable band gaps, high absorption over the visible spectrum, relatively long charge carrier diffusion lengths,, low exciton binding energies,, and low non‐radiative recombination losses ,. In order to fully exploit the potential of the perovskite light harvester, it needs to be embedded between effective electron and hole selective layers.…”