Effect of substrate temperature on microstructure and optical properties of single-phased Ag2O film deposited by using radio-frequency reactive magnetron sputtering method

Using a radio-frequency reactive magnetron sputtering technique,a series of the single-phased Ag2O films are deposited in a mixture of oxygen and argon gas with a flow ratio of 2:3 by changing substrate temperature(T s).Effects of the T s on the microstructure and optical properties of the films are investigated by using X-ray diffractometry,scanning electron microscopy and spectrophotometry.The single-phased Ag2O films deposited at values of T s below 200℃ are(111) preferentially oriented,which may be due to the smallest free energy of the(111) crystalline face.The film crystallization becomes poor as the value of T s increases from 100℃ to 225℃.In particular,the Ag2O film deposited at T s = 225℃ loses the 111 preferential orientation.Correspondingly,the film surface morphology obviously evolves from a uniform and compact surface structure to a loose and gullied surface structure.With the increase of T s value,the transmissivity and the reflectivity of the films in the transparent region are gradually reduced,while the absorptivity gradually increases,which may be attributed to an evolution of the crystalline structure and the surface morphology of the films.     

Preparing Cu2ZnSnS4 films using the co-electro-deposition method with ionic liquids

Cu2ZnSnS4（CZTS） films are successfully prepared by co-electrodeposition in aqueous ionic solution and sulfurized in elemental sulfur vapor ambient at 400 C for 30 min using nitrogen as the protective gas.It is found that the CZTS film synthesized at Cu/（Zn＋Sn）=0.71 has a kesterite structure,a bandgap of about 1.51 eV,and an absorption coefficient of the order of 10 4 cm 1.This indicates that the co-electrodeposition method with aqueous ionic solution is a viable process for the growth of CZTS films for application in photovoltaic devices.     

快速光热退火法制备多晶硅薄膜的研究

为了制备应用于太阳电池的优质多晶硅薄膜,研究了非晶硅薄膜的快速光热退火技术。先利用 PECVD 设备沉积非晶硅薄膜,然后放入快速光热退火炉中进行退火。退火前后的薄膜利用 X 射线衍射仪(XRD)和扫描电子显微镜(SEM)测试其晶体结构及表面形貌,用电导率设备测试其暗电导率。研究表明退火温度、退火时间对非晶硅薄膜的晶化都有很大的影响,光热退火前先用常规高温炉预热有助于增大多晶硅薄膜的晶粒尺寸和暗电导率。     

微晶硅薄膜的结构及光学性质的研究

借助RF-PECVD辅助RTP技术，采用高沉积气压的技术路线制备了优质的微晶硅薄膜，并利用拉曼光谱、反射谱和透射谱分别研究了微晶硅的晶化率和光学性质.实验中发现微晶硅的吸收边出现了相对红移，此相对红移可归结于薄膜晶化率的提高和带尾态密度的降低. 关键词： 微晶硅 拉曼光谱 快速热处理 红移     

Raman散射和AFM对多晶硅薄结晶状况的研究

采用等离子体增强化学气相沉积(PECVD)法在普通玻璃衬底上制备了多晶硅(p-si)薄膜。利用拉曼(Raman)散射谱、原子力显微镜(AFM)研究了衬底温度、射频功率和SiH4浓度对薄膜晶化的影响,并对其结果进行分析讨论。研究结果表明,当衬底温度从200℃逐渐提高到400℃、SiH4浓度从5%降到1%,硅膜的晶化率逐渐提高,结构逐渐由非晶向多晶转变,射频功率对薄膜的晶化状况也有很大影响。     

非晶硅太阳电池宽光谱陷光结构的优化设计

陷光是改善薄膜太阳电池光吸收进而提高其效率的关键技术之一. 以非晶硅（α-Si）薄膜太阳电池为例,设计了一种新的复合陷光结构：在Ag背电极与硅薄膜之间制备一维Ag纳米光栅,并通过保形生长在电池前表面沉积织构的减反膜. 采用有限元数值模拟方法,研究了该复合陷光结构对电池光吸收的影响,并对Ag纳米光栅的结构参数进行了优化. 模拟结果表明：该复合陷光结构可在宽光谱范围内较大地提高太阳电池的光吸收;当Ag纳米光栅的周期P为600 nm,高度H为90 nm,宽度W为180 nm时,在AM1.5光谱垂直入射条件下α-Si薄膜电池在300–800 nm波长范围内总的光吸收较无陷光结构的参考电池提高达103%,其中在650–750 nm长波范围内的光子吸收率提高达300%以上. 结合电场强度分布,对电池在各个波段光吸收提高的物理机制进行了分析. 另外,该复合陷光结构的引入,还较大地改善了非晶硅电池对太阳光入射角度的敏感性. 关键词： 非晶硅太阳电池 陷光 银纳米光栅 数值模拟     

Influence of Boron doping on microcrystalline silicon growth

Microcrystalline silicon (μc-Si:H) thin films with and without boron doping are deposited using the radio-frequency plasma-enhanced chemical vapour deposition method. The surface roughness evolutions of the silicon thin films are investigated using ex situ spectroscopic ellipsometry and an atomic force microscope. It is shown that the growth exponent β and the roughness exponent α are about 0.369 and 0.95 for the undoped thin film, respectively. Whereas, for the boron-doped μc-Si:H thin film, β increases to 0.534 and α decreases to 0.46 due to the shadowing effect.     

Effects of the sputtering power on the crystalline structure and optical properties of the silver oxide films deposited using direct-current reactive magnetron sputtering

This paper reports that a series of silver oxide (Ag_xO) films are deposited on glass substrates by direct-current reactive magnetron sputtering at a substrate temperature of 250 oC and an oxygen flux ratio of 15:18 by modifying the sputtering power (SP). The Ag_xO films deposited apparently show a structural evolution from cubic biphased (AgO + Ag₂O) to cubic single-phased (Ag₂O), and to biphased (Ag₂O + AgO) structure. Notably, the cubic single-phased Ag₂O film is deposited at the SP = 105 W and an AgO phase with <220> orientation discerned in the Ag_xO films deposited using the SP > 105 W. The transmissivity and reflectivity of the Ag_xO films in transparent region decrease with the increase the SP, whereas the absorptivity inversely increases with the increase of the SP. These results may be due to the structural evolution and the increasing film thickness. A redshift of the films' absorption edges determined in terms of Tauc formula clearly occurs from 3.1 eV to 2.73 eV with the increase of the SP.     

大面积多晶硅绒面的制备

采用酸腐蚀法,在小面积(2cm×2cm)多晶硅绒面制作的基础上,成功地在大面积(10cm×10cm)多晶硅片表面上制作了绒面.利用扫描电子显微镜(SEM)观察其表面形貌并进行反射谱测试,结果表明腐蚀比较均匀,表面减反射效果较好,加权反射率可以达到5.26%,其减反射效果对入射光波长选择性不明显,远好于工业生产用的SiN减反膜.     

快速光热退火制备多晶硅薄膜

用等离子体增强型化学气相沉积先得到非晶硅薄膜,再用卤钨灯照射的方法对其进行快速光热退火,得到了多晶硅薄膜,它与传统退火相比,退火时间大大缩短.用XRD衍射谱、暗电导率和拉曼光谱等手段对其进行了测量.对部分样品的照射光做了滤波,滤掉了波长600 nm以下的光,发现这对晶化及晶粒尺寸都有一定的影响.