从P-a-SiC:H到P-μc-Si:H过程中材料特性的变化

采用RF-PECVD方法,在P-a-SiC:H薄膜沉积技术基础上,通过逐步减小碳、硼的掺杂浓度,增大氢稀释率,使材料从非晶态向微晶态转变,在获得本征微晶材料之后,再逐步增大硼掺杂浓度,得到P型微晶硅薄膜材料(暗电导率为5.22×10-3S/cm,光学带隙大于2.0eV).在这个过程中可以明显观察到碳、硼抑制材料晶化的作用.     

SiO2阻挡层对电子束沉积法生长高迁移率IWO薄膜性能的影响

利用电子束沉积技术在玻璃衬底上制备了IWO( In2O3∶WO3)薄膜和SiO2缓冲层,并将SiO2缓冲层对IWO薄膜性能的影响作了探究.SiO2缓冲层在室温生长.SIMS测试表明:SiO2缓冲层能有效阻挡浮法玻璃中的杂质进入到IWO薄膜.实验获得的具有SiO2阻挡层的IWO薄膜的电子迁移率μ～54.5 cm2·V-1·s-1,电阻率p ～5.86×10-4Ω,cm,电子载流子浓度n～ 1.95×1020 cm-3,400～1600nm砌光谱区域内的平均透过率～76;.     

ITO薄膜的厚度对其光电性能的影响

氧化铟锡(indium-tin oxide, ITO)具有在可见光范围内高度透明的特性和优良的电学特性,通常当作透明电极,被广泛应用于太阳电池和发光元器件上.本研究中用电阻加热反应蒸发的方法制备ITO薄膜,测试了膜的厚度、电阻率、可见光透过率、载流子浓度和迁移率,讨论薄膜的厚度对薄膜光电性能的影响.实验中制备的ITO薄膜,透过率良好,电阻率可达6.37×10-4Ω·cm,载流子浓度和迁移率可分别达到1.91×1020cm-3和66.4cm2v-1s-1.将实验中制备的ITO作为nip太阳能电池透明电极,其短路电流为10.13mA/cm2,开路电压为0.79V,填充因子为0.648,效率可达到5.193;.     

B掺杂对平面结构MOCVD-ZnO薄膜性能的影响

本文研究了B2H6掺杂流量(B掺杂)对平面结构MOCVD-ZnO薄膜的微观结构和光电性能影响.XRD、SEM和AFM测试的研究结果表明,玻璃衬底上制备的ZnO薄膜具有(002)峰择优取向的平面结构,B掺杂使薄膜的球状晶粒尺寸变小,10 sccm流量时晶粒尺寸为～15 nm.ZnO:B薄膜的最小电阻率为5.7×10-3Ω·cm.生长的ZnO薄膜(厚度d=1150 nm)在400～900 nm范围的透过率为82;～97;,且随着B2H6掺杂流量增大,光学吸收边呈现蓝移(即光学带隙Eg展宽)现象.     

利用AAS研究农田土壤Cu,Zn和Cd含量及收支平衡

以沈阳生态实验站一组长期定位试验为平台,研究长期施用厩肥对农田土壤Cu,Zn和Cd含量及收支平衡的影响,试验处理分别为CK(不施有机肥),M1(施10 t·ha-1有机肥)、M2(施用量25 t·ha-1) 和M3 (施用量50 t·ha-1)。结果表明：长期施用厩肥会造成土壤中Cu,Zn和Cd的逐步积累,且积累量随着施肥量的提高而增加,三种重金属在各处理中(CK,M1,M2,M3)的年均增长率分别为2.83%,6.56%,7.54%,8.96%;0.03%,3.44%,4.53%,6.64%和1.51%,8.01%,10.27%,16.08%。从试验开始6年后,M3处理土壤Cd含量已非常接近国家三级土壤质量标准的限制阈值(1 mg·kg-1,GB15618—1995);至试验第12年,所有施有机肥处理的土壤Cu含量均降为国家三级土壤质量标准(≤400 mg·kg-1),因此必须给予足够的重视。尽管土壤中重金属呈逐年积累态势,但籽实中Cu,Zn和Cd含量均远低于国家食品污染标准(GB2762—2005; GB13106—91; GB15199—94),表明重金属超标农田生产的农产品未必超标。Cu,Zn和Cd在作物秸秆中的含量远大于籽实中含量,不同处理作物重金属平均移出量表现为M3＞M2＞M1＞CK。CK,M1,M2,M3处理Cu,Zn和Cd的年均移出量分别为35.68,47.80,63.65,69.64;249.14,375.22,375.16,444.44和0.83,1.39,1.64,1.66 g·ha-1。有机肥中重金属含量也随年份而改变,表现为Cu和Zn含量逐年增加,Cd含量呈减少态势。M1,M2和M3处理土壤年平均残留Cu,Zn和Cd量为2 283.0,5 763.7,11 585.4;2 483.3,6 771.4,13 849.2和4.8,13.9,29.5 g·ha-1,但是由于有机肥中重金属量年际变化范围较大,年平均残留量只能反映多年的平均趋势,准确推断土壤中重金属残留量还要根据当年施入的有机肥的情况而定。     

基于隧穿氧化物钝化接触的高效晶体硅太阳电池的研究现状与展望

在当今的光伏市场,晶体硅电池占据超过九成的份额,并且被认为在未来将依旧占据主导地位.在高效晶硅电池中,隧穿氧化物钝化接触太阳电池(tunnel oxide passivated contact solar cell,TOPCon)因其优异的表面钝化效果以及与传统产线兼容性好的优势而受到持续关注.该电池最显著的特征是其高...     

Influence of the deposition parameters on the transition region of hydrogenated silicon films growth

Hydrogenated microcrystalline and amorphous silicon thin films were prepared by very high frequency plasmaenhanced chemical vapour deposition （VHF PECVD） by using a mixture of silane and hydrogen as source gas. The influence of deposition parameters on the transition region of hydrogenated silicon films growth was investigated by varying the silane concentration （SC）, plasma power （Pw）, working pressure （P）, and substrate temperature （Ts）. Results suggest that SC and Ts are the most critical factors that affect the film structure transition from microcrystalline to amorphous phase. A narrow region in the range of SC and Ts, in which the rapid phase transition takes place, was identified. It was found that at lower P or higher Pw, the transition region is shifted to larger SC. In addition, the dark conductivity and photoconductivity decrease with SC and show sharp changes in the transition region. It proposed that the transition process and the transition region are determined by the competition between the etching effect of atomic hydrogen and the growth of amorphous phase.     

Reduction of the phosphorus contamination for plasma deposition of p-i-n microcrystalline silicon solar cells in a single chamber

This paper investigates several pretreatment techniques used to reduce the phosphorus contamination between solar cells. They include hydrogen plasma pretreatment, deposition of a p-type doped layer, i-a-Si:H or μc-Si:H covering layer between solar cells. Their effectiveness for the pretreatment is evaluated by means of phosphorus concentration in films, the dark conductivity of p-layer properties and cell performance.     

非晶硅锗电池性能的调控研究

采用射频等离子体增强化学气相沉积技术, 研究了非晶硅锗薄膜太阳电池. 针对非晶硅锗薄膜材料的本身特性, 通过调控硅锗合金中硅锗的比例, 实现了对硅锗薄膜太阳电池中开路电压和短路电流密度的分别控制. 借助于本征层硅锗材料帯隙梯度的设计, 获得了可有效用于多结叠层电池中的非晶硅锗电池. 关键词： 非晶硅锗薄膜太阳电池 短路电流密度 开路电压 带隙梯度     

Effect of substrate temperature and pressure on properties of microcrystalline silicon films

In this paper intrinsic microcrystalline silicon films have been prepared by very high frequency plasma enhanced chemical vapour deposition (VHF-PECVD) with different substrate temperature and pressure. The film properties were investigated by using Raman spectra, x-ray diffraction, scanning electron microscope (SEM), and optical transmittance measurements, as well as dark conductivity. Raman results indicate that increase of substrate temperature improves the microcrystallinity of the film. The crystallinity is improved when the pressure increases from 50Pa to 80Pa and the structure transits from microcrystalline to amorphous silicon for pressure higher than 80Pa. SEM reveals the effect of substrate temperature and pressure on surface morphology.