Textured perovskite cells
- PDF / 1,363,467 Bytes
- 8 Pages / 612 x 792 pts (letter) Page_size
- 73 Downloads / 170 Views
Textured perovskite cells Joop van Deelen1, Y. Tezsevin1, M. Barink2 1 Solliance/TNO, High Tech Campus, 21, 5656 AE, Eindhoven, The Netherlands. 2 Holst Centre/TNO, High Tech Campus 31, 5656 AE, Eindhoven, The Netherlands ABSTRACT Most research of texturization of solar cells has been devoted to Si based cells. For perovskites, it was assumed that texturization would not have much of an impact because of the relatively low refractive indexes lead to relatively low reflection as compared to the Si based cells. However, our optical modeling shows that a significant gain in perovskite (1.55 Ev) absorption from 84.6% to 93.5% for the wavelength range of 400 nm up to 800 nm. The largest gain in absorption is achieved between wavelengths of 700 nm and 800 nm. Because this is a range with a high photon density, the current density increases up to 10rel.%. We have modeled different sine texture sizes and show generic trends in performance with texture. Moreover, by introducing a texture, the light is locally concentrated, depending on the texture configuration. This offers new cell architectures with optimized front and back contacts. INTRODUCTION Perovskite cells are under intense investigation because of its relatively easy manufacturing process and promising efficiency gains over the last few years [1,2]. Most of the research is dedicated to making a good layer stack and stability issues [3-5]. The optical optimization has received relatively little attention. As the absorber has a lower refractive index compared to for instance Si, there is relatively low internal reflection. Moreover, the high absorption coefficient leads to much absorption in a relatively thin layer. For this reason, the perovskite field has shown no concern with the light capturing. However, one should realize that virtually all of the published cells make use of a mirror at the back. Therefore, the layer thickness requirement for the perovskite is below 500 nm. Nevertheless, for flat devices there are considerable light losses, as we will show, and it is relevant to check the potential for texturization as it can reduce the internal reflection and might lead to increased incoupling of the light. This can also be beneficial for cell configurations without back mirror, such as in semitransparent or tandem cells [6-11]. Moreover, as back contact cells have also found their way into thin film cells [12], it is interesting to see if texture can enable favorable lateral and vertical current generation distribution from which such novel panel architectures could benefit. This work shows the impact of texture on the performance of the perovskite solar cells by optical modeling. Various textures are compared with flat case and configurations with and without mirror at the back side are reviewed. This contribution is not aimed to explain the optical phenomena in detail. Instead, we show the effect of texture on the absorption, which is a resultant of the optical phenomena and relate that to the output of solar cells in order to investigate whether texturizati
Data Loading...
