Impact of Ge deposition temperature on parameters of c-Si solar cells with surface texture formed by etching of Si using SiGe islands as a mask. (1st August 2020)

• Record Type: Journal Article
• Authors: Nguyen, V.H.; Novikov, A.; Shaleev, M.; Yurasov, D.; Semma, M.; Gotoh, K.; Kurokawa, Y.; Usami, N.
• Is Part Of: Materials science in semiconductor processing. Volume 114(2020)
• Publication Date: 2020-08-01
• Subjects: Semiconductors -- Periodicals; Integrated circuits -- Materials -- Periodicals; Semiconducteurs -- Périodiques; Circuits intégrés -- Matériaux -- Périodiques; Electronic journals; 621.38152
• DOI: 10.1016/j.mssp.2020.105065
• Languages: English
• ISSNs: 1369-8001

Abstract

Abstract: In this paper, the Ge self-assembled islands grown at different temperatures were used as an etching mask for selective anisotropic etching of crystalline silicon (c-Si) in order to form a textured Si surface. The effects of Ge deposition temperature on the texture morphology as well as the parameters of c-Si solar cells fabricated on such structures were studied with the range of temperature from 500 °C to 800 °C. The textures on Si surface with low (<1 μm) etching margin were successfully fabricated for all investigated structures. It was revealed that usage of rapid annealing of Si wafer at 800 °C prior to epitaxial growth along with the low Ge deposition temperature of 500 °C allowed to achieve the relatively high effective carrier lifetime as compared to structures formed at higher (≥700 °C) temperatures thanks to the reduced degradation of Si wafer characteristics. Furthermore, the structure obtained using the lowest deposition temperature of 500 °C exhibited the highest light absorption among all studied samples thanks to the most homogeneous and most pyramidal texture morphology. As a result, the calculated short circuit current density J SC for the sample in which Ge islands were grown at 500 °C was as high as 35.89 mA/cm 2 . The proposed approach of surface texturing meets the requirements for thin c-Si solar cells due to small etching margin and the obtained results pave the way for increase the efficiency of thin c-Si solar cells by engineering the surface morphology to improve light absorption.