Predicting the Interface Morphologies of Silicon Films on Arbitrary Substrates: Application in Solar Cells

Abstract

A three-dimensional model that predicts the interface morphologies of silicon thin-film solar cells prepared on randomly textured substrates was developed and compared to experimental data. The surface morphologies of silicon solar cells were calculated by using atomic force microscope scans of the textured substrates and the film thickness as input data. Calculated surface morphologies of silicon solar cells are in good agreement with experimentally measured morphologies. A detailed description of the solar cell interface morphologies is necessary to understand light-trapping in silicon single junction and micromorph tandem thin-film solar cells and derive optimal light-trapping structures.

Effect of back reflectors on photon absorption in thin-film amorphous silicon solar cells

“…Because of the low absorption coefficient of amorphous silicon for longer wavelength (k = 700 nm), light needs to finish numerous path in the solar cell. The approaching light achieves the back contact of the sunbased cell, where it gets reflected and completed different paths inside the solar cell (Dewan et al 2012;Jovanov et al 2013c;Tamang et al 2016b). From Fig.…”

On the potential of light trapping in multiscale textured thin film solar cells

“…For the multiscale textured substrates, the glass substrate is modeled by hexagonally arranged concave craters. The surface morphology of FTCO layer is determined by the surface coverage algorithm [25,26] because the growth of the ZnO:B film deposited by LPCVD process takes place in the direction of local surface normal [27]. The resulting microtextures of the FTCO layer have diameters of almost 3 mm and height of 1.2 mm.…”

“…In recent years, the formation of silicon thin film solar cells on nanoscale textured substrates has been studied. Different models have been proposed to describe the film growth and interface morphologies of silicon thin films deposited on textured substrates [11,15,16,25,26,28,29]. Most of the studies have shown that amorphous silicon grows (almost entirely) in the direction of a local surface normal.…”

“…4(d) and (f) exhibits the surface after the deposition of a 300 nm thick amorphous silicon film obtained by the surface coverage algorithm. Details on the surface coverage algorithm and its accuracy can be found in the literature [25,26]. In previous studies, simulated and measured surfaces have been compared exhibiting a good agreement [25,26].…”

An image processing approach to approximating interface textures of microcrystalline silicon layers grown on existing aluminum-doped zinc oxide textures

“…The model was recently enhanced by directional growth factors for simulating columnar µc-Si growth while neglecting so-called nanofeatures (cf. [7]). The distinction between columnar growth and nanofeatures is important, as the columnar film growth is directional and in principle covered by existing models, while nanofeatures arise in a less predictable fashion.…”