Broadband Transparent Front Electrodes for Perovskite Silicon Tandem Solar Cells

Broadband Transparent Front Electrodes for Perovskite Silicon Tandem Solar Cells

Internship Description

This project is focusing on developing novel transparent electrodes for perovskite/silicon tandem solar cells which are an emerging class of solar cells technology. Perovskite/silicon tandem solar cells aim to achieve the power conversion efficiencies beyond the single junction limit of the silicon solar cells. Towards this end, developing highly transparent electrodes are critical for the maximized light harvesting since parasitic absorption loses originating from the transparent conductive oxides causes drastic current losses.

 

In this project, the deposition of the novel transparent conductive oxides will be performed the sputtering technique. The candidate will gain experience on the structural, optical and electrical and characterization of the thin films. Moreover, the candidate will have experience in the fabrication and characterization of the perovskite/silicon tandem solar cells to test the developed materials.

 

Why we need broadband transparent electrodes on perovskite/silicon tandem solar cells?

In perovskite/silicon tandem solar cells, the perovskite top cell efficiently harvests the blue part of the solar spectrum, while transmitting the red part, which is absorbed in the silicon bottom cell. In this way, the tandems can overcome the single-junction efficiency limit of silicon solar cells. However, parasitic absorption losses originating from the transparent electrodes hinders the light harvesting. Typically, a front transparent electrode in any solar cell has a sufficiently large (>3 eV) optical band gap to avoid absorption losses in the visible range of the spectrum. This requirement is already fulfilled by several TCOs such as ITO, IZO, and IO: H. For perovskite/silicon tandem solar cells, transparent electrodes with low absorptance in the NIR‐IR part of the spectrum are required since these devices use optical absorbers that are active in this range of the spectrum. Towards reaching >30% photoconversion efficiency, designing transparent electrodes with exceptionally large broadband transparency carriers critical importance.


References

[1] Morales‐Masis, M., De Wolf, S., Woods‐Robinson, R., Ager, J. W., & Ballif, C. (2017). Transparent electrodes for efficient optoelectronics. Advanced Electronic Materials, 3(5), 1600529.

Deliverables/Expectations

Optimization of the sputtering parameters of H:In2O3 and IZO transparent electrodes

Optical and electrical characterization of the fabricated films

Achieving <20 ohm/sq. sheet resistivity for 1000 nm thickness together with broadband transparency (<10% absorbance within this region).

Exploring new TCO by metal doping of In2O3

Faculty Name

Stefaan De Wolf

Field of Study

Solar Cells