Low-cost potassium hydroxide texturing of monocrystalline silicon: a response surface methodology approach for solar cell application

Improved light trapping and minimal surface reflectance are needed for higher conversion efficiency of the solar cell. Proposed research work has been focused on reducing the light reflection from the substrate. The fabrication of pyramidal structures on the surface of monocrystalline Si (100) wafers is an effective approach for reducing front-surface reflection losses in traditional silicon solar cells. Alkaline solutions are often used for texturing monocrystalline silicon. Tetramethylammonium hydroxide (TMAH) and potassium hydroxide (KOH) are the predominant etchants utilized in the wet anisotropic etching procedure. One of the two etchants, KOH is an economical option that offers significant etch rate anisotropy between Si (100) and Si (111) planes. Enhancing the etch rate is a significant research challenge for both industrial and academic purposes. This research examines the influence of polyvinyl alcohol (PVA) in 1wt% KOH on the etching properties of Si (100). A systematic parametric analysis was performed by adding several concentrations of PVA (0.1%, 0.3%, and 0.5%) to a 1 wt% KOH solution. Texturing was conducted at 100 °C for 20, 30, and 40 mins. The response surface methodology (RSM) suggests solution concentrations as process factors. Without using an antireflection (ARC) layer, an efficient surface texture with average reflectance of 9.05 % was obtained. The antireflection behavior was additionally correlated to the silicon etch rate. RSM indicated optimal values for PVA concentration and time of 0.1% and 30 mins, respectively. Optimizing the strategy and parameters for texturizing high-efficiency silicon solar cells by response surface methodology may prove beneficial. Reflectance was calculated by the diffuse reflectance spectrophotometer (DRS). The surface morphology of Si (100) wafers was examined using scanning electron microscopy