The B- and P-doped hydrogenated nanocrystalline silicon films （nc-Si：H） are prepared by plasma-enhanced chemical vapour deposition （PECVD）. The microstructures of doped nc-Si＇H films are carefully and systematic...The B- and P-doped hydrogenated nanocrystalline silicon films （nc-Si：H） are prepared by plasma-enhanced chemical vapour deposition （PECVD）. The microstructures of doped nc-Si＇H films are carefully and systematically characterized by using high resolution electron microscopy （HREM）, Raman scattering, x-ray diffraction （XRD）, Auger electron spectroscopy （AES）, and resonant nucleus reaction （RNR）. The results show that as the doping concentration of PH3 increases, the average grain size （d） tends to decrease and the crystalline volume percentage （Xc） increases simultaneously. For the B-doped samples, as the doping concentration of B2H6 increases, no obvious change in the value of d is observed, but the value of Xc is found to decrease. This is especially apparent in the case of heavy B2H6 doped samples, where the films change from nanocrystalline to amorphous.展开更多
The early stages of hydrogenated nanocrystalline silicon （nc-Si：H） films deposited by plasma-enhanced chemical vapour deposition were characterized by atomic force microscopy. To increase the density of nanocrystal...The early stages of hydrogenated nanocrystalline silicon （nc-Si：H） films deposited by plasma-enhanced chemical vapour deposition were characterized by atomic force microscopy. To increase the density of nanocrystals in the nc-Si：H films, the films were annealed by rapid thermal annealing （RTA） at different temperatures and then analysed by Raman spectroscopy. It was found that the recrystallization process of the film was optimal at around 1000℃. The effects of different RTA conditions on charge storage were characterized by capacitance-voltage measurement. Experimental results show that nc-Si：H films obtained by RTA have good charge storage characteristics for nonvolatile memory.展开更多
The enhanced optical absorption measured by Constant Photocurrent Method (CPM) of hydrogenated nanocrystalline silicon thin films is due mainly to bulk and/or surface light scattering effects. A new numerical method i...The enhanced optical absorption measured by Constant Photocurrent Method (CPM) of hydrogenated nanocrystalline silicon thin films is due mainly to bulk and/or surface light scattering effects. A new numerical method is presented to calculate both true optical absorption and scattering coefficient from CPM absorption spectra of nanotextured nano-crystalline silicon films. Bulk and surface light scattering contributions can be unified through the correlation obtained between the scattering coefficient and surface roughness obtained using our method.展开更多
Hydrogenated amorphous silicon （a-Si：H） films with high and same order of magnitude photosensitivity （-10^5） but different stability were prepared by using microwave electron cyclotron resonance chemical vapour d...Hydrogenated amorphous silicon （a-Si：H） films with high and same order of magnitude photosensitivity （-10^5） but different stability were prepared by using microwave electron cyclotron resonance chemical vapour deposition system under the different deposition conditions. It was proposed that there was no direct correlation between the photosensitivity and the hydrogen content （CH） as well as H-Si bonding configurations, but for the stability, they were the critical factors. The experimental results indicated that higher substrate temperature, hydrogen dilution ratio and lower deposition rate played an important role in improving the microstructure of a-Si：H films. We used hydrogen elimination model to explain our experimental results.展开更多
Hydrogenated silicon （Si：H） thin films for application in solar ceils were deposited by using very high frequency plasma enhanced chemical vapour deposition （VHF PECVD） at a substrate temperature of about 170 ℃,...Hydrogenated silicon （Si：H） thin films for application in solar ceils were deposited by using very high frequency plasma enhanced chemical vapour deposition （VHF PECVD） at a substrate temperature of about 170 ℃, The electrical, structural, and optical properties of the films were investigated. The deposited films were then applied as i-layers for p-i-n single junction solar cells. The current-voltage （I - V） characteristics of the cells were measured before and after the light soaking. The results suggest that the films deposited near the transition region have an optimum properties for application in solar cells. The cell with an i-layer prepared near the transition region shows the best stable performance.展开更多
Hydrogenated nanocrystalline silicon thin films were fabricated from Sill4 with H2 dilution at a low substrate temperature of 200℃ by the conventional plasma enhanced chemical vapor deposition technique. A high depos...Hydrogenated nanocrystalline silicon thin films were fabricated from Sill4 with H2 dilution at a low substrate temperature of 200℃ by the conventional plasma enhanced chemical vapor deposition technique. A high deposition rate over 0.75 nm/s can be achieved. Raman scattering spectral measurements revealed that the crystalline fraction and grain size increased with the increase in hydrogen dilution ratio. Fourier transform infrared spectrum measurements showed that the hydrogen content decreased and the Si-H bonding configuration changed mainly from Sill to Sill2 with the increase in hydrogen dilution ratio. This suggested that the hydrogen dilution played an important role in the low-temperature growth of nanocrystalline silicon thin film. The growth mechanism is discussed in terms of a surface diffusion model and hydrogen etching effects.展开更多
该研究制备高电导、高透明的磷掺杂氢化纳米晶硅氧(nc-Si Ox:H)薄膜,应用于晶硅异质结(SHJ)太阳电池的窗口层以替代传统的氢化非晶硅(a-Si:H)薄膜。与以a-Si:H薄膜为窗口层的电池相比,短路电流密度提高0.5 m A/cm^(2),达到38.5 m A/cm^(...该研究制备高电导、高透明的磷掺杂氢化纳米晶硅氧(nc-Si Ox:H)薄膜,应用于晶硅异质结(SHJ)太阳电池的窗口层以替代传统的氢化非晶硅(a-Si:H)薄膜。与以a-Si:H薄膜为窗口层的电池相比,短路电流密度提高0.5 m A/cm^(2),达到38.5 m A/cm^(2),填充因子为82.7%,光电转换效率为23.5%。实验发现,在nc-Si Ox:H薄膜沉积前对本征非晶硅层表面进行处理,沉积1 nm纳米晶硅(nc-Si:H)种子层,可改善nc-Si Ox:H薄膜的晶化率,降低薄膜中的非晶相含量。与单层nc-Si Ox:H窗口层的电池相比,nc-Si:H/nc-Si Ox:H叠层结构提高电池填充因子,达到83.4%,光电转换效率增加了0.3%,达到23.8%。展开更多
基金Project supported by the National Natural Science Foundation of China （Grant No 10432050）.
文摘The B- and P-doped hydrogenated nanocrystalline silicon films （nc-Si：H） are prepared by plasma-enhanced chemical vapour deposition （PECVD）. The microstructures of doped nc-Si＇H films are carefully and systematically characterized by using high resolution electron microscopy （HREM）, Raman scattering, x-ray diffraction （XRD）, Auger electron spectroscopy （AES）, and resonant nucleus reaction （RNR）. The results show that as the doping concentration of PH3 increases, the average grain size （d） tends to decrease and the crystalline volume percentage （Xc） increases simultaneously. For the B-doped samples, as the doping concentration of B2H6 increases, no obvious change in the value of d is observed, but the value of Xc is found to decrease. This is especially apparent in the case of heavy B2H6 doped samples, where the films change from nanocrystalline to amorphous.
基金Project supported by the National Basic Research Program of China （973 Program） （Grant No 2006CB302706） and the National Natural Science Foundation of China （Grant Nos 90607022, 904010027 90207004, and 60506005）.
文摘The early stages of hydrogenated nanocrystalline silicon （nc-Si：H） films deposited by plasma-enhanced chemical vapour deposition were characterized by atomic force microscopy. To increase the density of nanocrystals in the nc-Si：H films, the films were annealed by rapid thermal annealing （RTA） at different temperatures and then analysed by Raman spectroscopy. It was found that the recrystallization process of the film was optimal at around 1000℃. The effects of different RTA conditions on charge storage were characterized by capacitance-voltage measurement. Experimental results show that nc-Si：H films obtained by RTA have good charge storage characteristics for nonvolatile memory.
文摘The enhanced optical absorption measured by Constant Photocurrent Method (CPM) of hydrogenated nanocrystalline silicon thin films is due mainly to bulk and/or surface light scattering effects. A new numerical method is presented to calculate both true optical absorption and scattering coefficient from CPM absorption spectra of nanotextured nano-crystalline silicon films. Bulk and surface light scattering contributions can be unified through the correlation obtained between the scattering coefficient and surface roughness obtained using our method.
文摘Hydrogenated amorphous silicon （a-Si：H） films with high and same order of magnitude photosensitivity （-10^5） but different stability were prepared by using microwave electron cyclotron resonance chemical vapour deposition system under the different deposition conditions. It was proposed that there was no direct correlation between the photosensitivity and the hydrogen content （CH） as well as H-Si bonding configurations, but for the stability, they were the critical factors. The experimental results indicated that higher substrate temperature, hydrogen dilution ratio and lower deposition rate played an important role in improving the microstructure of a-Si：H films. We used hydrogen elimination model to explain our experimental results.
文摘Hydrogenated silicon （Si：H） thin films for application in solar ceils were deposited by using very high frequency plasma enhanced chemical vapour deposition （VHF PECVD） at a substrate temperature of about 170 ℃, The electrical, structural, and optical properties of the films were investigated. The deposited films were then applied as i-layers for p-i-n single junction solar cells. The current-voltage （I - V） characteristics of the cells were measured before and after the light soaking. The results suggest that the films deposited near the transition region have an optimum properties for application in solar cells. The cell with an i-layer prepared near the transition region shows the best stable performance.
基金supported by the Major State Basic Research and Development Program of China,Ministry of Science and Technology of China (No.G2000028208)
文摘Hydrogenated nanocrystalline silicon thin films were fabricated from Sill4 with H2 dilution at a low substrate temperature of 200℃ by the conventional plasma enhanced chemical vapor deposition technique. A high deposition rate over 0.75 nm/s can be achieved. Raman scattering spectral measurements revealed that the crystalline fraction and grain size increased with the increase in hydrogen dilution ratio. Fourier transform infrared spectrum measurements showed that the hydrogen content decreased and the Si-H bonding configuration changed mainly from Sill to Sill2 with the increase in hydrogen dilution ratio. This suggested that the hydrogen dilution played an important role in the low-temperature growth of nanocrystalline silicon thin film. The growth mechanism is discussed in terms of a surface diffusion model and hydrogen etching effects.
