金属Cr阻挡层对柔性不锈钢衬底Cu(In,Ga)Se2太阳电池性能的影响

研究了Cr扩散阻挡层对柔性不锈钢衬底Cu(InxGa1-x)Se2(CIGS)太阳电池性能的影响.XRD和SEM分析表明,Cr阻挡层能够部分阻挡Fe等杂质从不锈钢衬底热扩散进入CIGS吸收层中,同时可以显著降低CIGS吸收层的粗糙度,提高薄膜结晶质量.从衬底扩散进入吸收层中的Fe元素以FeInSe2的形式存在,并形成FeCu等深能级缺陷,钝化了器件的性能.相同工艺条件下,在玻璃、不锈钢以及不锈钢/Cr阻挡层上所制备电池的(有效面积0.87cm2)转换效率分别为10.7%,7.95%和8.58%,不锈钢衬底电池效率的提高归因于Cr阻挡层的作用.     

衬底对Cu(In,Ga)Se2薄膜织构的影响

分别在苏打石灰玻璃、Mo箔、无择优取向的Mo薄膜以及(110)择优取向的Mo薄膜四种不同衬底上，采用共蒸发工艺沉积约2 μm厚的Cu(In,Ga)Se₂薄膜，用X射线衍射仪测量薄膜的织构，研究衬底对Cu(In,Ga)Se₂薄膜织构的影响.在以上四种衬底上沉积的Cu(In,Ga)Se₂薄膜的(112)衍射峰强度依次逐渐减弱，(220/204)衍射峰从无到有且强度逐渐增强.在苏打石灰玻璃和Mo箔衬底上的Cu(In,Ga)Se_{2关键词： 择优取向 Cu(In 2}薄膜')" href="#">Ga)Se₂薄膜 太阳电池     

Mo Back Contact for Flexible Polyimide Substrate Cu（In,Ga）Se2 Thin-Film Solar Cells

A dc magnetic sputtering process is applied to growth of a Mo back. contact layer onto the flexible polyimide （PI） and rigid soda-lime glass （SLC） substrates. The structural and electrical properties of the Mo layer coated on the two kinds of substrates are investigated by x-ray diffraction （XRD） and Hall effect measurements. The results show that the Mo layer on SLG indicate more better crystal quality and lower resistivity than that on the PI sheets. In contrast to the SLG substrate, the resistivity of the Mo layer on PI is increased by the vacuum annealing process at the substrate temperature of 450℃ under Se atmosphere, which is attributed to the cracked Mo layer induced by the mismatch of the coefficient of thermal expansion between PI and Mo material. The Cu（In,Ga）Se2 （CIGS） solar cells based on the PI and SLO substrates show the best conversion efficiencies of 8.16% and 10.98% （active area, 0.2cm^2）, respectively. The cell efficiency of flexible CIGS solar cells on PI is limited by its relatively lower fill factor caused by the Mo back contact.     

Raman scattering of polycrystalline GaSb thin films grownby co-evapouration process

<正>This paper reports that GaSb thin films have been co-deposited on soda-lime glass substrates.The GaSb thin film structural properties are characterized by Raman spectroscopy.The Sb-A_1g/GaSb-TO ratio decreases rapidly with the increase of substrate temperature,which suggests a small amount of crystalline Sb in the GaSb thin film and suggests that Sb atoms in the thin film decrease.In Raman spectra,the transverse optical（TO） mode intensity is stronger than that of the longitudinal optical（LO） mode,which indicates that all the samples are disordered.The LO/TO intensity ratio increases with increasing substrate temperature which suggests the improved polycrystalline quality of the GaSb thin film.A downshift of the TO and LO frequencies of the polycrystalline GaSb thin film to single crystalline bulk GaSb Raman spectra is also observed.The uniaxial stress in GaSb thin film is calculated and the value is around 1.0 GPa.The uniaxial stress decreases with increasing substrate temperature.These results suggest that a higher substrate temperature is beneficial in relaxing the stress in GaSb thin film.     

Cu(In,Ga)Se2薄膜太阳电池二极管特性的研究

本文采用线性拟合光态和暗态J-V(电流-电压)曲线的方法计算了不同效率的Cu(In,Ga)Se2(CIGS)薄膜太阳电池的二极管性能参数.在一定范围内,CIGS薄膜电池的二极管品质因子A和反向饱和电流J0值越小,电池的转换效率越高,这说明CIGS电池的复合主要发生在PN结区内.量子效率分析表明,不同效率的CIGS电池在短波区(λ<520 nm)的光谱响应相差不大,而在长波区(520～1100 nm),低效率电池存在很大的吸收,这是由低质量的CIGS吸收层造成的.这进一步验证了光-暗态J-V曲线的分析结果,即高质量的吸收层是制备CIGS电池的关键.     

多晶Cu(In,Ga)Se2薄膜太阳电池光强特性的研究

本文系统研究了Cu(In,Ga)Se2(CIGS)薄膜太阳电池在入射光强为10～100 mW/cm2范围内的性能参数.结果表明,随光强的减弱,CIGS电池的转换效率、填充因子、短路电流密度和开路电压等性能参数逐步衰减;电池参数与光强的依赖关系可明显划分为两个阶段:光强高于75 mW/cm2时,电池性能变化不大;当光强低于70 mW/cm2时,电池性能衰减明显.这是由于随着光强的降低,RS(串联电阻)值和RSH(并联电阻)值都在升高.其中,RSH值的增大使得CIGS电池的弱光特性变好,但较小的RSH值并不能弥补RS所导致电池性能的衰退.最后,发现高Ga含量的CIGS薄膜电池(8.7;)比低Ga含量(6.9;)的电池弱光特性好.     

无定形锗硅合金的光电特性

用射频溅射方法制备了无定形锗硅合金 a-Si_(1-x)Ge_x: H膜的光学带隙随x值的增加而单调下降.用最小二乘法将光学带隙数据作线性拟合得到E_g(eV)=1.79-0.98x.当膜中锗的原子百分比从0增加到66％时,合金膜室温暗电导率从10~(-10)Q~(-1)cm~(-1)单调上升到10~(-4)Q~(-1)·cm~(-1);电导激活能却从0.84eV单调下降到0.40eV. 用XPS 谱测量合金组分证明锗的溅射速率是硅的1.5倍.测量了光子能量为1.2eV时的吸收系数,结果表明,a-Si(1-x)Ge_x:H比a-Si:H有较多的悬挂键.这些悬挂键在较高氢分压下可部分被饱和.     

金属Cr阻挡层对柔性不锈钢衬底Cu(In,Ga)Se2太阳电池性能的影响

研究了Cr扩散阻挡层对柔性不锈钢衬底Cu(InxGa1-x)Se2(CIGS)太阳电池性能的影响.XRD和SEM分析表明,Cr阻挡层能够部分阻挡Fe等杂质从不锈钢衬底热扩散进入CIGS吸收层中,同时可以显著降低CIGS吸收层的粗糙度,提高薄膜结晶质量.从衬底扩散进入吸收层中的Fe元素以FeInSe2的形式存在,并形成FeCu等深能级缺陷,钝化了器件的性能.相同工艺条件下,在玻璃、不锈钢以及不锈钢/Cr阻挡层上所制备电池的(有效面积0.87cm2)转换效率分别为10.7%,7.95%和8.58%,不锈钢衬底电池效率的提高归因于Cr阻挡层的作用.     

Cu(In1-xGax)Se2薄膜太阳电池的J-V特性

对Cu（In1-xGax）Se2（CIGS）太阳电池J-V特性曲线进行了测试和分析,采用Matlab软件进行计算,得到电池的二极管品质因子、反向饱和电流密度、串联电阻、并联电阻等特性参数，采用数值逼近法,将得到的参数回归J-V方程,与测试结果符合较好，对不同光照强度下电池的特性参数进行计算,发现并联电阻随光照强度增加而降低,并分析了原因。     

The effect of composition on structural and electronic properties in polycrystalline CuGaSe2 thin film

Polycrystalline CuGaSe2 thin films on Mo-coated soda-lime glass substrates have been synthesized by coevaporation process from Cu, Ga and Se sources. Structural and electrical properties of the as-grown CuGaSe2 films strongly depend on the film composition. Stoichiometric CuGaSe2 is fabricated, as indicated by x-ray diffraction spectroscope （XRD） and x-ray fluorescence （XRF）. A two-phase region is composed of CuGaSe2 and Cu2-xSe phases for Cu-rich films, and CuGaSe2 and CuGa3Se5 phases for Ga-rich films, respectively. Morphological properties are detected by scanning electron microscope （SEM） for various compositional films, the grain sizes of the CuGaSe2films decrease with the extent of deviation from stoichiometric composition. Raman spectroscopy of Cu-rich samples shows that there exist large Cu-Se particles on the film surface. The results from Hall effect measurements for typical samples indicate that CuGaSe2 films are always of p-type semiconductor from Cu-rich to Ga-rich. Stoichiometric CuGaSe2 films exhibit relatively large mobility than any other compositional films. Finally, polycrystalline CuGaSe2 thin film solar cell with a best conversion efficiency of 6.02% has been achieved under the standard air mass （AM）1.5 spectrum for 100mW/cm^2 at room temperature （aperture area, 0.24cm^2）. The open circuit voltage of the CuGaSe2 solar cells is close to770 mV.