“…Among many techniques to solve the aforementioned two problems, catalytic doping (Cat-doping) is a cheap, simple, and industrially feasible postdeposition doping method, which is based on the hot wire chemical vapor deposition (HWCVD) process . Doping gases, such as phosphine (PH 3 ) and diborane (B 2 H 6 ), are catalytically decomposed at the hot surface of the filaments into phosphorous (P) and boron (B) radicals. , The radicals move from the filament surface to the sample surface and then diffuse into the silicon material films, forming a shallow depth doping layer with a thickness of 5–20 nm. − Therefore, it is possible to replace the deposition of the doped silicon layer by Cat-doping on the intrinsic layer, which reduces the parasitic absorption of doped silicon layers. Former studies have shown that the material properties, such as conductivity and doping concentration, can be further tuned beyond the level that is achievable for as-grown films. ,, It has also been reported that the passivation quality of SHJ structures could be improved with Cat-doping on different interfaces, such as at the c-Si, a-Si:H(i), and doped silicon layer surfaces in a SHJ structure. ,,,− …”