Nd³⁺:YAG laser assisted doping and simultaneous texturization of amorphous Si film for tandem photovoltaic cell

A textured Sb-doped a-Si film is synthesised using laser-assisted doping combined with texturing for a photovoltaic cell application. The amorphous silicon films coated with Sb to a thickness of 200-300 nm are treated intially with a threshold laser fluence of 460 mJ/cm2 for dopant diffusion. To reactivate the dopant, the samples are retreated with a lower laser fluence of 230 mJ/cm2. The laser diffusion and dopant activation are performed by overlapping the laser spots to 90% of its size, so as to subsequently induce texture on the surface. Generation of polycrystalline textured peaks is confirmed with different characterization methods, such as SEM, Raman Spectroscopy, AFM, resistance and absorbance measurements. Treated samples show a crystalline peak of 521 cm-1 with Raman spectroscopy taken from the front and back of the sample. The n-type characteristics of the samples is confirmed through Hall effect measurements, which confirms also the efficient doping. Surface texture with a roughness parameter of 450 nm and improvement in photocondcutivity and absorbance spectroscopy values are observed, which confirmes the improved photovoltaic properties of the samples.