晶硅衬底参数对背接触太阳电池性能的影响

利用Silvaco-TCAD半导体器件仿真软件对n型插指背接触(IBC)晶硅太阳电池衬底参数进行了优化,全面系统地分析了晶硅衬底厚度、电阻率、少子寿命对IBC太阳电池量子效率、短路电流、开路电压、转换效率的影响.结果表明:晶硅衬底少子寿命是影响IBC太阳电池性能的最主要因素.少子寿命越高,电池转换效率越高.当晶硅衬底电阻率为2Ω·cm,少子寿命为500 μs时,最优的衬底厚度范围为60～65μm,IBC太阳电池转换效率约为22.5％.利用高质量晶硅材料制备IBC太阳电池时,可降低对衬底厚度的要求.当晶硅衬底厚度为150 μm、少子寿命为500μs时,最优衬底电阻率为0.3 Ω·cm,IBC太阳电池转换效率约为23.3％.少子寿命越低,IBC太阳电池最优的衬底电阻率越大.     

前结背接触晶硅太阳电池发射区研究

利用Silvaco-TCAD仿真软件全面系统地分析了发射区表面浓度(cE)、结深(xj)及发射区覆盖比率(EF)对P型前结背接触晶硅太阳电池输出特性的影响。结果表明:基于常规低成本P型晶硅衬底(利用直拉法生长,电阻率为1.5?·cm,少子寿命为10μs)的前结背接触太阳电池,其上表面发射区表面浓度及结深对太阳电池的输出特性产生显著影响。上表面发射区表面浓度和结深越大,短波入射光外量子效率越小。当上表面发射区表面浓度为1×1019 cm–3,结深为0.2μm时,电池效率高达20.72%。侧面和下表面发射区表面浓度及结深对太阳电池输出特性的影响较小。但侧面和下表面发射区覆盖比率对太阳电池的输出特性产生显著影响。侧面和下表面发射区覆盖比率越大,太阳电池外量子效率和转换效率越高。     

背接触太阳电池发射区设计及可靠性研究

利用Silvaco-TCAD仿真软件全面系统地分析了不同发射区表面浓度和结深对n型插指背接触(IBC)太阳电池短路电流、开路电压、填充因子及转换效率的影响.借鉴双极半导体器件抗二次击穿技术,详细分析了不同发射区结深、发射区边缘刻蚀技术和发射区边缘选择性掺杂技术对IBC电池热击穿特性的影响.结果表明:发射区表面浓度越大、结深越深,IBC电池效率越高.当发射区表面浓度为5× 1020 cm-3、结深为1 μm时,转换效率高达23.35％.同时,深结发射区也有助于改善IBC电池的热击穿特性.发射区边缘刻蚀结构不具有改善IBC电池热击穿特性的作用,而发射区边缘选择性掺杂结构可有效改善IBC电池的热击穿特性,从而提高IBC太阳电池组件的可靠性.     

n型异质结背接触太阳电池前表面的场钝化

利用Silvaco-TCAD仿真软件建立二维模型,对n型异质结背接触(HBC)单晶硅太阳电池前表面场进行模拟研究。通过在n型单晶硅衬底正面分别引入一层较薄的本征非晶硅层和一层n+非晶硅层对电池前表面进行高质量的场钝化,分析了n+非晶硅层的厚度和掺杂浓度以及本征非晶硅层的厚度和带隙宽度对电池电学性能的影响。模拟结果表明:当n+非晶硅层厚度小于6 nm,掺杂浓度为1×1019 cm-3,本征非晶硅层的厚度为3 nm,带隙宽度大于1.5 eV时,电池前表面实现了良好的场钝化效果,HBC太阳电池获得了24.5%的转换效率。     

CdS/CdTe太阳电池的背接触

磷硝酸腐蚀是一种适宜于工业化生产的背表面刻蚀工艺.文中采用磷硝酸腐蚀CdTe薄膜,并用溴甲醇腐蚀作为对照实验,研究了两种腐蚀对材料性质的影响.随后用真空蒸发法分别沉积了四种背接触层,提出了适宜于工业化生产的背接触技术,并从实验和理论上对两种背接触结构的CdTe太阳电池进行了分析.     

N 型背接触晶硅太阳电池前表面场研究

利用 Silvaco 公司的 Athena 工艺仿真软件和 Atlas 器件仿真软件,对 N 型插指背结背接触(InterdigitatedBack Contact,IBC)晶硅太阳电池普遍采用的前表面场（FSF）结构进行研究,详细分析了 IBC 晶硅电池 FSF 表面掺杂浓度及扩散深度对电池性能的影响。结果表明：具有不同表面掺杂浓度和扩散深度的 FSF 对 IBC 晶硅太阳电池短路电流密度(Jsc)、开路电压(Voc)和填充因子(FF)产生显著影响,从而影响电池的转换效率(Eff)。具有较低表面浓度、深扩散 FSF 结构的 IBC 晶硅太阳电池可获得较高转换效率,当表面掺杂浓度为 5×1017cm–3时,电池转换效率Eff最高,且随 FSF 扩散深度增加略有增加,最高转换效率可达 22.3%。     

CdS/CdTe太阳电池的背接触

磷硝酸腐蚀是一种适宜于工业化生产的背表面刻蚀工艺.文中采用磷硝酸腐蚀CdTe薄膜,并用溴甲醇腐蚀作为对照实验,研究了两种腐蚀对材料性质的影响.随后用真空蒸发法分别沉积了四种背接触层,提出了适宜于工业化生产的背接触技术,并从实验和理论上对两种背接触结构的CdTe太阳电池进行了分析.     

局部背接触结构单晶Si太阳电池的研究

报道了采用局部背接触结构的激光刻槽埋栅太阳电池的研究结果.模拟分析了局部背接触结构的作用,设计了合理的电池结构.通过工艺优化,得到了转换效率达到17.28%(大气质量AM=1.5 G,VOC=650.4mV,JSC=33.15 mA/cm2,FF=0.8014,电池面积为4 cm2)的太阳电池.     

CuxS背接触层制备及在碲化镉薄膜太阳电池中应用研究

本文采用化学水浴法沉积CuxS薄膜,通过改变Cu元素比例研究其对碲化镉电池效率的影响。研究表明化学水浴法沉积的CuxS是非晶的,采用适当退火条件可以使其晶化,随着退火温度的提高,薄膜变得致密且结晶明显。CuxS薄膜厚度对电池性能有很大的影响,结果表明,随着CuxS薄膜厚度增加,电池性能先增加后减少。薄膜厚度为75nm时,CdS/CdTe电池性能最佳,达到了最高转化效率(η)为12.19%,填充因子(FF)为68.82%,开路电压(Voc)为820mV。     

多晶硅太阳电池背表面刻蚀提升其性能的产线工艺研究

对比研究了产线上多晶硅太阳电池背表面刻蚀对 其光电转换性能的影响。示范性实验结果表明:多晶硅太阳电池背表面刻蚀能够改善其短路 电流, 从而相应的光电转换效 率提升了约 0．1％。依据多晶硅太阳电池背表面刻蚀前后的扫描 电镜(SEM)形貌、背表面漫 反射光谱及完整电池片外量子效率的测试结果,改进的光电转换的原因可能源于背表面刻蚀 “镜面”化有利于太阳光子在背表面内反射和改进印刷Al浆与背表面覆盖接触。背表面刻蚀 与当前晶硅电池产线工艺兼容,能够提升电池片的光电转换效率,是一种可供选择的产线升 级工艺。     

Silicon point contact concentrator solar cells

Experimental results are presented for thin high resistivity concentrator silicon solar cells which use a back-side point-contact geometry. Cells of 130 and 233 µm thickness were fabricated and characterized. The thin cells were found to have efficiencies greater than 22 percent for incident solar intensities of 3 to 30 W/cm²(30-300 "suns"). Efficiency peaked at 23 percent at 11 W/cm²measured at 22-25°C. Strategies for obtaining higher efficiencies with this solar cell design are discussed.     

An interdigitated back contact solar cell with high-current collection

Internal current-collection efficiencies greater than 90 percent and energy-conversion efficiencies of 18-percent at 30 suns have been measured on a laboratory version of the interdigitated back contact (IBC) solar cell. The quantum efficiency at 600 nm was greater than 90 percent which implies a minority carrier lifetime of greater than 350 µsec and a front surface recombination velocity of less than 30 cm/sec on the better devices. The processing steps on which the high-current collection in the IBC cell depends will be discussed.     

n-Si bifacial concentrator solar cell

Various approaches have been developed for reducing the cost of the photoelectricity produced by silicon solar cells (SCs). Of highest priority among these approaches are improvement of the efficiency of the SCs, transition from p-Si to n-Si, light concentration, and use of bifacial SCs. In the present study, an SC combining all these approaches has been developed. In this SC, transparent conducting oxides serve as antireflection and passivating electrodes in an indium-tin-oxide/(p ⁺ nn ⁺)-Si/indium-fluorine-oxide structure fabricated from Cz-Si with wire contacts (Laminated Grid Cell design). The SC has front/rear efficiencies of 16.5?C16.7/15.1?C15.3% X (under 1?C3 suns). This result is unique because the combination of bifaciality and concentrator operation has no analogs and the SC compares well with the world standard among both bifacial and concentrator SCs.     

Large area, concentrator buried contact solar cells

Considerable interest has been shown commercially in the buried contact solar cell (BCSC) approach, particularly for large area one-sun cells and large area concentrator cells. Efficiencies in the range of 21-22% have been independently confirmed by Sandia National Laboratories for a 20-cm² device operating at 20 suns using prismatic covers. An alternative, innovative approach for groove and metallization formation has enabled the demonstration of similar efficiencies but without the use of prismatic covers. These are believed to be the highest reported efficiencies by a clear margin for any concentrator cell of this size     

光强和温度对多结太阳电池的影响研究

基于模拟太阳光源的方法,在室内研究了在不同光照强度、不同工作温度下GaAs多结太阳电池的输出特性.通过实验得出:随着光源辐照强度的增加,太阳电池的特性参数:短路电流Isc线性增加,开路电压Voc对数增加,最大输出功率P线性增加,光电转换效率η随聚光比增加到一定程度后减小.对比分析了光强和温度对电池输出特性的影响,数据结...     

The interdigitated back contact solar cell: A silicon solar cell for use in concentrated sunlight

The theoretical and experimental performance of an interdigitated back contact solar cell is described. This type of cell is shown to have significant advantages over a conventional solar cell design when used at high concentration levels, namely, reduced internal series resistance, nonsaturating open-circuit voltage, and an absence of shadowing by front surface contacting fingers. The results of a computer study are presented showing the effects of bulk lifetime, surface recombination velocity, device thickness, contact dimensions, and illumination intensity on the conversion efficiency and general device operation. Experimental results are presented for solar illumination intensities up to 28 W/cm².     

Low-cost back contact silicon solar cells

Back-contacted solar cells offer multiple advantages in regard of reducing module assembling costs and avoiding grid shadowing losses. The investigated emitter-wrap-through (EWT) device design has an electrical connection of the front emitter and the rear emitter grid in form of small holes drilled into the crystalline silicon wafer. The obtained cell structure is especially suitable for low-cost base material with small minority carrier diffusion lengths. Different industrially applicable solar cell manufacturing processes for EWT devices are described and compared. The latest experimental results are presented and interpreted; the photocurrent is found to be distinctly increased. The relation between open circuit voltage and rear side passivation is discussed based on two-dimensional (2-D) computer simulations     

Mechanical problems of novel back contact solar modules

The mechanical integrity of interconnect structures of different types of photovoltaic modules is analyzed by FEM-simulations. The goal is to develop a systematic understanding of the potential thermo-mechanical damage by a detailed theoretical analysis of the mechanical behavior of important structural elements in photovoltaic modules. The results of this investigation allow to identify critical locations in the photovoltaic module assembly that limit the module lifetime.