This title appears in the Scientific Report :
2020
Photovoltaic performance of metal-halide perovskites – what is general and what is special?
Photovoltaic performance of metal-halide perovskites – what is general and what is special?
After many decades of photovoltaic research we would expect that there should be a common scientific understanding on the necessary ingredients to make almost perfect solar cells. However, the unprecedented success of metal-halide perovskites (MHPs) stimulated discussions on whether there could be a...
Saved in:
Personal Name(s): | Rau, Uwe (Corresponding author) |
---|---|
Contributing Institute: |
Photovoltaik; IEK-5 |
Imprint: |
2020
|
Conference: | 2020 MRS Virtual Spring/Fall Meeting & Exhibit, virtual (USA), 2020-11-27 - 2020-12-04 |
Document Type: |
Conference Presentation |
Research Program: |
Solar cells of the next generation |
Publikationsportal JuSER |
After many decades of photovoltaic research we would expect that there should be a common scientific understanding on the necessary ingredients to make almost perfect solar cells. However, the unprecedented success of metal-halide perovskites (MHPs) stimulated discussions on whether there could be a certain, yet non-established secret that distinguishes this material from others. The present contribution compares the performance of MHPs to other photovoltaic materials in terms of a general top-down approach. This direct comparison allows one to judge the strengths and weaknesses of different technologies but also gives some insight on the specific achievements, e.g. that, on the one hand, the radiative yield of MHPs is second only to the best GaAs solar cells, which implies open circuit voltages that come close to the thermodynamic limits. On the other hand the relative contribution of fill factor losses to the overall efficiency losses in MHPs is relatively large compared to most other technologies. Fill factor issues can generally originate from recombination or voltage losses during charge carrier collection, both aspects playing a role for MHPs. This issue will be discussed in terms of new, general models for the charge carrier separation in solar cells. Finally, the question will be addressed whether specific bulk properties of MHPs, like the presence of an indirect band gap, the density of states, or small phonon energies could be of importance for their favorable photovoltaic behavior. |