Highly conductive boron-doped hydrogenated mieroerystalline silicon (μc-Si:H) films are prepared by very high frequency plasma enhanced chemical vapour deposition (VHF PECVD) at the substrate temperatures (Ts)...Highly conductive boron-doped hydrogenated mieroerystalline silicon (μc-Si:H) films are prepared by very high frequency plasma enhanced chemical vapour deposition (VHF PECVD) at the substrate temperatures (Ts) ranging from 90℃ to 270℃. The effects of Ts on the growth and properties of the films are investigated. Results indicate that the growth rate, the electrical (dark conductivity, carrier concentration and Hall mobility) and structural (crystallinity and grain size) properties are all strongly dependent on Ts. As Ts increases, it is observed that 1) the growth rate initially increases and then arrives at a maximum value of 13.3 nm/min at Ts=210℃, 2) the crystalline volume fraction (Xc) and the grain size increase initially, then reach their maximum values at TS=140℃, and finally decrease, 3) the dark conductivity (σd), carrier concentration and Hall mobility have a similar dependence on Ts and arrive at their maximum values at Ts-190℃. In addition, it is also observed that at a lower substrate temperature Ts, a higher dopant concentration is required in order to obtain a maximum σd.展开更多
This paper found that the crystalline volume ratio (Xc) of μc-Si deposited on SiNx substrate is higher than that on 7059 glass. At the same silane concentration (SC) (for example, at SC=2%), the Xc of μc-Si de...This paper found that the crystalline volume ratio (Xc) of μc-Si deposited on SiNx substrate is higher than that on 7059 glass. At the same silane concentration (SC) (for example, at SC=2%), the Xc of μc-Si deposited on SiNx is more than 64%, but just 44% if deposited on Conning 7059. It considered that the ‘hills' on SiNx substrate would promote the crystalline growth of μc-Si thin film, which has been confirmed by atomic force microscope (AFM) observation. Comparing several thin film transistor (TFT) samples whose active-layer were deposited under various SC, this paper found that the appropriate SC for the μc-Si thin film used in TFT as active layer should be more than 2%, and Xc should be around 50%. Additionally, the stability comparison of μc-Si TFT and a-Si TFT is shown in this paper.展开更多
Using diborane as doping gas, p-doped μc-Si:H layers are deposited by using the plasma enhanced chemical vapour deposition (PECVD) technology. The effects of deposition pressure and plasma power on the growth and ...Using diborane as doping gas, p-doped μc-Si:H layers are deposited by using the plasma enhanced chemical vapour deposition (PECVD) technology. The effects of deposition pressure and plasma power on the growth and the properties of μc-Si:H layers are investigated. The results show that the deposition rate, the electrical and the structural properties are all strongly dependent on deposition pressure and plasma power. Boron-doped μc-Si:H films with a dark conductivity as high as 1.42 Ω^-1·cm^-1 and a crystallinity of above 50% are obtained. With this p-layer, μc-Si:H solar cells are fabricated. In addition, the mechanism for the effects of deposition pressure and plasma power on the growth and the properties of boron-doped μc-Si:H layers is discussed.展开更多
Highly conductive boron-doped hydrogenated microcrystalline silicon (μc-Si: H) films and solar cells are pre- pared by plasma enhanced chemical vapour deposition (PECVD). The effects of diborane concentration, t...Highly conductive boron-doped hydrogenated microcrystalline silicon (μc-Si: H) films and solar cells are pre- pared by plasma enhanced chemical vapour deposition (PECVD). The effects of diborane concentration, thickness and substrate temperature on the growth and properties of B-doped layers and the performance of solar cells with high deposited rate i-layers are investigated. With the optimum p-layer deposition parameters, a higher efficiency of 5.5% is obtained with 0.78nm/s deposited i-layers. In addition, the carriers transport mechanism of p-type μc-Si: H films is discussed.展开更多
文摘Highly conductive boron-doped hydrogenated mieroerystalline silicon (μc-Si:H) films are prepared by very high frequency plasma enhanced chemical vapour deposition (VHF PECVD) at the substrate temperatures (Ts) ranging from 90℃ to 270℃. The effects of Ts on the growth and properties of the films are investigated. Results indicate that the growth rate, the electrical (dark conductivity, carrier concentration and Hall mobility) and structural (crystallinity and grain size) properties are all strongly dependent on Ts. As Ts increases, it is observed that 1) the growth rate initially increases and then arrives at a maximum value of 13.3 nm/min at Ts=210℃, 2) the crystalline volume fraction (Xc) and the grain size increase initially, then reach their maximum values at TS=140℃, and finally decrease, 3) the dark conductivity (σd), carrier concentration and Hall mobility have a similar dependence on Ts and arrive at their maximum values at Ts-190℃. In addition, it is also observed that at a lower substrate temperature Ts, a higher dopant concentration is required in order to obtain a maximum σd.
基金Project supported by the ‘863' Project of National Ministry of Science and Technology (Grant No 2004AA33570), Key Project of NSFC (Grant No 60437030) and Tianjin Natural Science Foundation (Grant No 05YFJMJC01400).
文摘This paper found that the crystalline volume ratio (Xc) of μc-Si deposited on SiNx substrate is higher than that on 7059 glass. At the same silane concentration (SC) (for example, at SC=2%), the Xc of μc-Si deposited on SiNx is more than 64%, but just 44% if deposited on Conning 7059. It considered that the ‘hills' on SiNx substrate would promote the crystalline growth of μc-Si thin film, which has been confirmed by atomic force microscope (AFM) observation. Comparing several thin film transistor (TFT) samples whose active-layer were deposited under various SC, this paper found that the appropriate SC for the μc-Si thin film used in TFT as active layer should be more than 2%, and Xc should be around 50%. Additionally, the stability comparison of μc-Si TFT and a-Si TFT is shown in this paper.
基金Project supported by the State Key Development Program for Basic Research of China (Grant No 2006CB202601)Basic Research Project of Henan province,China (Grant No 072300410140)
文摘Using diborane as doping gas, p-doped μc-Si:H layers are deposited by using the plasma enhanced chemical vapour deposition (PECVD) technology. The effects of deposition pressure and plasma power on the growth and the properties of μc-Si:H layers are investigated. The results show that the deposition rate, the electrical and the structural properties are all strongly dependent on deposition pressure and plasma power. Boron-doped μc-Si:H films with a dark conductivity as high as 1.42 Ω^-1·cm^-1 and a crystallinity of above 50% are obtained. With this p-layer, μc-Si:H solar cells are fabricated. In addition, the mechanism for the effects of deposition pressure and plasma power on the growth and the properties of boron-doped μc-Si:H layers is discussed.
基金the State Key Development Program for Basic Research of China(No.2006CB202601)the Basic Research Project of Henan Province(No.072300410140)~~
文摘Highly conductive boron-doped hydrogenated microcrystalline silicon (μc-Si: H) films and solar cells are pre- pared by plasma enhanced chemical vapour deposition (PECVD). The effects of diborane concentration, thickness and substrate temperature on the growth and properties of B-doped layers and the performance of solar cells with high deposited rate i-layers are investigated. With the optimum p-layer deposition parameters, a higher efficiency of 5.5% is obtained with 0.78nm/s deposited i-layers. In addition, the carriers transport mechanism of p-type μc-Si: H films is discussed.