Influence of Al2O3/IZO double-layer antireflective coating on the front side of rear emitter silicon heterojunction solar cell

Transparent conductive oxide (TCO) thin films play a significant role in silicon heterojunction (SHJ) solar cell and perform both as antireflection coating (ARC) and carrier transport layer. Indium zinc oxide (IZO) films have attracted much attention in opto-electronic industry as an alternative TCO material owing to their superior optical and electrical characteristics as compared to conventionally used indium tin oxide (ITO) films. The optical and electrical properties of IZO films were studied and compared with ITO films. Moreover, the dielectric layer of Al2O3 was deposited on the IZO films using an atomic layer deposition (ALD) system to prepare a double layer antireflection coating (DLARC) structure. The wafer ray tracer simulation tool was used to optimize the thickness of Al2O3/IZO DLARC for SHJ solar cells and experimental results showed its validation. The performance of Al2O3/IZO DLARC on the front surface of rear emitter SHJ solar cell recorded to increase in the current density of 1.37% with enhancement in the efficiency of 0.8%, showing noticeable improvement as compared to cell fabricated with single-layer IZO film. [Display omitted] •IZO showed showing high mobility and low sheet resistance as compared to ITO.•The Al2O3/IZO showed average reflectance (R‾) of 2.2% for 620 nm–1100 nm wavelength range (red and near Infrared regio).•Jsc for solar cell having Al2O3/IZO increased to 1.37% and η improved to 0.8% as compared to cell having only IZO layer.