Co-doping of Phosphorous-Boron in-situ grown c-Si quantum dots/a-SiOx:H thin films on PET

Phosphorus-boron co-doped amorphous hydrogenated silicon oxide (a-SiOx:H) thin films containing crystalline silicon quantum dot (c-Si QD) were prepared via plasma enhanced chemical vapor deposition (PECVD) route on polyethylene terephthalate (PET) substrate. With the aim of optimizing the doping efficiency and effectively controlling the properties of the flexible thin films, the helium (He) and argon (Ar) mixed dilution was applied in the in-situ deposition process. A series of characterizations have been carried out for studying the variation in the properties of flexible P-B co-doped Si QD/a-SiOx:H thin films when tuning the He/Ar flow ratio. Successful P-B co-doping has been proved according to the redshift of photoluminescence (PL) peak. Experimental results also show that the QD size and the doping concentration are controllable when varying the He/Ar flow ratio, while the PL peaks are tunable with QD size. Furthermore, the mechanisms on film growth and impurity doping were illustrated in detail.