16:45 〜 17:00
▼ [14p-A31-13] Growth of Crystalline BaSi2 Thin Films by Vacuum Evaporation on Poly-Crystalline Silicon Fabricated by Aluminum Induced Crystallization
キーワード：solar cells, thin films, BaSi2
We attempt to realize single-phase crystalline BaSi2 thin films on glass substrate by utilizing poly-Si layers fabricated by Aluminum Induced Crystallization (AIC) for solar cell applications. Vacuum evaporation method was chosen to deposit BaSi2 due to its simplicity and large deposition area. Since lumps of BaSi2 with 99% purity were used as source material, the content of the vapor during evaporation process is time-dependent: initial vapor is Ba rich, while the latter is Si rich. In spite of this fact, our previous studies revealed that single phase BaSi2 can be achieved on Si (111) substrates by solid-state reaction of Ba-rich layer with the Si substrate. In this study, poly-Si fabricated by AIC on glass substrate is employed as Si supply layers to form single-phase BaSi2. Since AIC proceeds under nearly equilibrium conditions, p-type Al doping of Si can be expected. Thus upon deposition of BaSi2, p-type BaSi2 is also conceivable.
During AIC process, large grained Si layer with preferred orientation of (111) is achieved at annealing temperature of 475 oC. However, the grain size becomes smaller and (001)-oriented regions grow at higher temperatures. Upon BaSi2 deposition, Raman spectra of the samples grown at substrate temperature of 400 oC and above show 5 characteristic peaks of BaSi2 which represent [Si4]4− anions vibration modes in BaSi2 phase. No other peaks were observed, which might indicates that the grown BaSi2 is single phase. Moreover, the electrical properties of the grown BaSi2 will be further investigated.
According to our results, BaSi2 was successfully grown on poly-Si layer fabricated by AIC method. The absence of peaks other than BaSi2 peaks on Raman spectra might indicates that the grown BaSi2 is single phase.
During AIC process, large grained Si layer with preferred orientation of (111) is achieved at annealing temperature of 475 oC. However, the grain size becomes smaller and (001)-oriented regions grow at higher temperatures. Upon BaSi2 deposition, Raman spectra of the samples grown at substrate temperature of 400 oC and above show 5 characteristic peaks of BaSi2 which represent [Si4]4− anions vibration modes in BaSi2 phase. No other peaks were observed, which might indicates that the grown BaSi2 is single phase. Moreover, the electrical properties of the grown BaSi2 will be further investigated.
According to our results, BaSi2 was successfully grown on poly-Si layer fabricated by AIC method. The absence of peaks other than BaSi2 peaks on Raman spectra might indicates that the grown BaSi2 is single phase.