太阳电池效率与串联电阻的近似指数关系

太阳电池的串联电阻对其效率有显著的影响。呈近似指数关系。串联电阻对填充因子有重要的影响。串联电阻。对太阳电池的卜一v特性进行数值分析，证明效率和串联电阻由实测的开路电压、短路电流和效率可以简便地数值计算确定     

测量方式对太阳电池输出性能测试的影响

通过对二线与四线接法测试单晶硅太阳电池I-V曲线的实验结果对比,分析串联内阻对于太阳电池短路电流、开路电压、填充因子及最大输出功率测量结果的影响。结果发现串联内阻越大,太阳电池的短路电流、填充因子及最大输出功率测量结果越小,但对开路电压基本无影响。且太阳电池接收光强越大即输出电流越大时,串联内阻的影响也越大。二线法因串联内阻较大,相较四线测量方法,在光强分别为1160.69、734.61、470.15和232.14 W/m²时,最大功率降幅分别为64.73%、40.26%、22.98%、11.88%;填充因子降幅分别为64.10%、40.96%、22.22%、12.66%。表明内阻大小影响二线及四线测量结果,四线法测量方式能有效规避串联引线电阻和部分接触电阻,是较理想的测量方式。     

太阳电池光电性能户外测试方法与测试仪器

提出了通过测量环境温度及自然阳光下标准太阳电池短路电流来确定太阳实际辐照度的方法,设计了太阳电池光电性能户外测试仪器,可在现场对太阳电池的I-U曲线、短路电流、开路电压、峰值功率、峰值功率点所对应的电流和电压、填充因子、光电转换效率和串联电阻等进行快速测量,并将各项测量结果转换为STC下的对应值。实践证明,该仪器使用方便,测量结果重复性好、精度高。     

多功能太阳电池电性能测试系统

多功能太阳电池电性能测试系统,采用大功率冷光灯做模拟太阳光源,对主机及样品架采取了有效的温控措施,并使用单板微处理机对测试结果进行联机实时处理,测试准确、快速、方便。 该系统主要由主机、I—V曲线显示和记录仪器、数据处理设备组成(图1),可综合测定(?)60以内各种规格太阳电池的电特性参数:开路电压V_(oc),短路电流I_(sc),最大功率输出P_m,最佳工作点电压V_(mp)和电流I_(mp),光电转换效率η,填充因子FF,最佳负载电阻R_L,串联电阻r,以及开路电压、短路电流、最大功率输出的温度系数等。系统方框图见图2。     

并联电阻及光电流随正向电压变化对a-Si:H集成太阳电池填充因子的影响

提出了一种简化的集成太阳电池等效电路,讨论了并联电阻及光电流随正向电压变化对填充因子的影响。并联电阻低或光电流随正向电压变化大的太阳电池,填充因子小。光电流随正向电压变化的大小由i层电荷密度决定。对于实验所用太阳电池,i层电荷密度在2×10~(15)cm~(-3)-3.5×10~(15)cm~(-3)之间。     

太阳电池串联电阻的解析解

太阳电池的串联电阻解析解及相应的I-V曲线可由实测的开路电压、短路电流及电压电流值从I-V方程直接得到,实测数据证明了该结论。     

活性层厚度及温度对有机太阳电池的数值分析

利用AMPS-1D软件研究以P3HT∶PCBM为活性层的异质结有机太阳电池的各项性能。仿真结果表明:器件的短路电流、开路电压、光电转换效率、载流子的复合率均随器件活性层厚度的增大而增大,但器件的填充因子和内建电场随厚度的增加而减小。温度影响开路电压,但对短路电流影响不大。通过曲线的拟合发现,填充因子随着活性层厚度的增加呈现一次指数衰减,光电转换效率呈现一次指数增加的趋势。     

几种硅基太阳能电池输出特性的测试与分析

对单晶硅、多晶硅、非晶硅三种太阳能电池输出特性进行了测量与分析,较为全面地研究了功率特性、伏安特性以及开路电压、短路电流、填充因子和转换效率与光强的关系等.揭示了一些参数之间的关系,如:存在最大输出功率Pm；UOC与G成对数关系,ISC与G成线性关系；ISC与UOC成指数关系；光强对FF和η影响不大等,并对如何提高光电...     

染料敏化太阳电池中电子传输性能

通过检测染料敏化TiO2纳米晶太阳电池中TiO2膜厚度和入射光的强度对电池光电转换性能的影响来研究电池中电子的传输性能。结果表明：TiO2膜厚度和入射光强度对电池性能有很大的影响。当TiO2膜厚度增大时，电池的短路电流(Isc)加大，而填充因子(ff)下降，开路电压(Voc)先上升后下降，电池的单色光光电转化效率(IPCE)增大；当光强度加大时，电池的短路电流和开路电压均增加，但是电池的填充因子降低。并用UV-Vis等手段表征了染料RuL2(SCN)2。     

基于数据手册的光伏电池特性及参数实用估算方法

利用光伏电池数据手册提供的标准测试条件下的开路电压、短路电流、最大功率点电压和最大功率点电流,得到光伏电池的详细模型参数;提出一种光伏电池模型的等效并联电阻和串联电阻的估算新方法。利用数据手册中的光伏电池短路电流和开路电压温度系数,得到了任意光强和任意温度下的光伏电池模型。为降低求解隐函数模型方程的复杂性,采用近似方法求解隐函数超越方程,得到了光伏电池模型显函数表达式。通过与两种光伏电池在不同光强和温度下的测试数据及同类模型的比较,验证了所提出的模型及参数估算方法的正确性、有效性,具有较高的精度。     

Dark I–U–T measurements of single crystalline silicon solar cells

The effect of parasitic resistances on silicon solar cell performance was discussed. The current–voltage I–U characteristics of single crystalline silicon solar cells at different temperatures were measured in the dark. A one and two diodes equivalent model was used to describe the electronic properties of the solar cells. The diode ideality factors, the series and shunt resistance, that determine the fill factor and the efficiency of the solar cell, have been estimated. It was proved that the performance of the tested silicon solar cell can be described with enough accuracy by the one diode equivalent model with series resistance r_s equal to 0.1 Ω and an empirical ideality factor m_id equal to 1.4.     

Defect states on the surfaces of a P-type c-Si wafer and how they control the performance of a double heterojunction solar cell

“Heterojunction with intrinsic thin layer” solar cells combine the high efficiency of crystalline silicon (c-Si) cells, with the low cost of amorphous silicon technology. Here we use detailed numerical modeling and experiments to understand the influence, on the solar cell output parameters, of defects on the front and rear surfaces of the P-type c-Si wafer. Modeling indicates that the defects on the front surface of c-Si reduce the open-circuit voltage and fill factor, while those on the rear surface degrade mainly the short-circuit current density and fill factor, but only when their density exceeds 10¹² cm⁻².     

Properties of an n-C:P/p-Si carbon-based photovoltaic cell grown by radio frequency plasma-enhanced chemical vapor deposition at room temperature

The phosphorus-doped amorphous carbon (n-C:P) films were grown by radiofrequency (RF) power-assisted plasma-enhanced chemical vapor deposition (PECVD) at room temperature using a solid phosphorus target. The influence of phosphorus doping on the material properties of n-C:P based on the results of simultaneous characterization are reported. Moreover, solar cell properties such as series resistance, short-circuit current density, open-circuit current voltage, fill factor and conversion efficiency along with the spectral response are reported for the fabricated carbon-based n-C:P/p-Si heterojunction solar cells by standard measurement technique. The cells’ performances have been given in the dark I–V rectifying curve and I–V working curve under illumination when exposed to AM 1.5 illumination condition (100 mW/cm², 25 °C). The maximum open-circuit voltage (V_oc) and short-circuit current density (J_sc) for the cells are observed to be approximately 236 V and 7.34 mA/cm², respectively, for the n-C:P/p-Si cell grown at a lower RF power of 100 W. The highest energy conversion efficiency (η) and fill factor (FF) were found to be approximately 0.84% and 49%, respectively. We have observed that the rectifying nature of the heterojunction structures is due to the nature of n-C:P films.     

Fill factor losses in ZnO/CdS/CuGaSe2 single-crystal solar cells

Current–voltage characteristics of ZnO/CdS/CuGaSe₂ single-crystal solar cells with solar conversion efficiency values of η=3.5%, 6.0%, 6.7% and 9.7% were analyzed using the single diode equation. The effect of each of the achieved parameters on the fill factor was calculated. The calculations revealed that the fill factor reduction due to the series resistance remained below Δff=4.4% under illumination, while this effect would have been much higher if the illumination had not reduced the series resistance markedly. The calculation furthermore revealed that the fill factor reduction due to the shunt resistance remained below Δff=3.6% under illumination. This effect would have been negligible if the illumination had not also reduced the shunt resistance in all studied cells. The increase of the saturation current density under illumination has brought about considerably high fill factor losses (at least Δff=8.3%) in all studied cells. Already the dark saturation current density and the diode ideality factor in such cells have been found to be much higher than the ones in the cells based on CuInSe₂. This seems to be the most substantial restriction to the fill factor, and thus to the performance, of solar cells based on CuGaSe₂. An explanation for this different behavior seems to lie in the different band structures of these cells.     

Effect of electrode geometry on the photovoltaic performance of dye-sensitized solar cells

Effect of electrode geometry on the photovoltaic performance of dye-sensitized solar cell (DSSC) has been investigated to optimize the device geometry for reliable energy conversion efficiency assessment. Mesoporous TiO₂ layers with an identical active area (0.40 cm²) and different dimension are prepared on FTO glass substrate by the screen printing method and used as photoanodes for DSSCs. Under 1 sun illumination (AM 1.5G, 100 mW cm⁻²), both the open-circuit voltage and the short-circuit current density are independent of electrode geometry whereas the fill factor and hence energy conversion efficiency show strong dependency. Electrochemical impedance spectroscopy analysis indicates that the distance between active layer and ohmic contact directly contributes to internal series resistance and influence photovoltaic performance.     

Effect of solvents in liquid electrolyte on the photovoltaic performance of dye-sensitized solar cells

The effect of solvents in liquid electrolyte on the photovoltaic performance of dye-sensitized solar cells was investigated. The solvents with large donor number enhanced the open-circuit voltage but reduced the short-circuit current density. By mixing 30 vol.% NMP with 70 vol.% GBL, the open-circuit voltage increased from 0.55 to 0.632 V and the fill factor increased from 0.607 to 0.613 while the short-circuit current density decreased little. The further addition of 0.4 M pyridine into the above mixed solvent caused a huge increase of overall conversion efficiency from 5.73 to 6.70% under irradiation of 100 mW cm⁻².     

Effect of operating current dependent series resistance on the fill factor of a solar cell

The fill factor of a solar cell depends upon the series resistance, reverse saturation current, diode quality factor, operating current and voltage. Since the series resistance itself depends upon the operating current (or voltage), it makes the evaluation of fill factor very complicated. In this paper, we have evaluated the fill factor of a solar cell, taking into account operating current dependence of the series resistance.     

Computer simulation of amorphous MIS solar cells

A computer model to simulate amorphous MIS solar cells is developed. The model is based on the self-consistent solution of the electron and hole continuity equations, together with the Poisson equation under proper boundary conditions. The program developed is used to investigate the cell performance characteristics in terms of its physical and structural parameters. The current-voltage characteristics of the solar cell are obtained under AM1 solar illumination. The dependences of the short-circuit current, open-circuit voltage, fill factor and cell conversion efficiency on localized gap state density, carrier lifetime, cell thickness and surface recombination velocity are obtained and discussed. The results presented show how cell parameters can be varied to improve the cell performance characteristics.