Development of solution-derived diffusion barrier layer for back-contact crystalline silicon solar cell

Interface Optoelectronics Engineering for Mechanically Stacked Tandem Solar Cells Based on Perovskite and Silicon

“…After spin-coating, the porous TiO 2 layer was annealed at 500 °C. For the deposition of the perovskite layer (CH 3 NH 3 ­PbI 3 ) using a two-step process, 1.2 M of PbI 2 was dissolved in N , N dimethyl­formamide by stirring at 70 °C, deposited on the mesoporous TiO 2 film by spin-coating at 6500 rpm for 20 s, and dried at 70 °C for 30 min. Then, the TiO 2 /PbI 2 film was dipped into a solution of CH 3 NH 3 I in isopropanol (10 mg/mL) for 20 s and spun to dry at 4000 rpm for 8 s (2 s of acceleration).…”

“…Finally, the deposited CH 3 NH 3 ­PbI 3 film was dried on a hot plate at 70 °C for 30 min. 2,2,7,7-Tetrakis­( N , N -di- p -methoxy­phenyl­amine)-9,9-spiro­bifluorene (spiro-OMeTAD) was deposited as an organic hole transporting material (HTM) according to the literature . The organic HTM solution was deposited using the spin-coating method at 4000 rpm for 8 s. Finally, gold was evaporated on top to form a gold layer with various thicknesses before processing to achieve the tandem structure.…”

“…First, all wafers were put through RCA cleaning and diluted HF dip. Then, prior to phosphorus diffusion, poly­silazane-based SiO 2 was coated on the rear side of the samples as a diffusion barrier by the spin-coating method at 1500 rpm for 20 s (accelerating 5 s) and annealed at 500 °C for 1 h under O 2 flow. , Phosphorus diffusion was carried out by annealing of the CZ-Si wafers at 890 °C for 20 min under nitrogen gas flow passed though POCl 3 liquid. After the diffusion process, phosphorus silica glass and the SiO 2 layer on the rear were removed by a diluted HF solution.…”