Open AccessFABRICATING AND TESTING BLACK SILICON SOLAR CELLS
Author(s) -
Gagik Ayvazyan,
A.V. Aghabekyan
Publication year - 2021
Language(s) - English
DOI - 10.53297/18293336-2021.1-73
Subject(s) - materials science , wafer , dopant , solar cell , silicon , optoelectronics , isotropic etching , quantum dot solar cell , doping , crystalline silicon , fabrication , etching (microfabrication) , thermal oxidation , layer (electronics) , polymer solar cell , nanotechnology , medicine , alternative medicine , pathology
Black Si (b-Si) is a needle-like surface of crystalline Si. The optical radiation incidenton it is almost completely absorbed due to multi-reflections from the side surfaces of the needles, which makes b-Si attractive for solar cell applications as antireflection surfaces. Currently, b-Si solar cells are fabricated based on the sequences used for traditional (pyramidal textured) solar cells, namely first, an antireflection surface is formed, and then high-temperature treatments such as oxidation and diffusion are carried out. However, in this case, due to large surface area, the diffusion of dopants within b-Si is much more efficient than in a planar, without texture, wafer. It leads to high doping concentrations and non-uniformity in the dopant. In addition, during the diffusion process, a surface layer of glass is grown, and subsequently removed by wet etching, which leads to noticeable changes in the morphology and structure of b-Si. As a result, after thermal and chemical treatments, the optical characteristics of the b-Si are retrogressed.A new fabrication sequence of b-Si solar cells has been proposed and tested, according to which, the b-Si with preferable height of needles is formed after the main chemicaland thermal treatments of the technological process. It has been shown that all performance parameters (open-circuit voltage, short current, fill factor and conversion efficiency) of the new b-Si solar cells are higher than those of the conventional solar cells. Joint use of b-Si and pyramidal textured surfaces can get a more tangible effect.