Performance enhancement of ZnO nanowires/PbS quantum dot depleted bulk heterojunction solar cells with an ultrathin Al_2O_3 interlayer

Depleted bulk heterojunction(DBH)PbS quantum dot solar cells(QDSCs),appearing with boosted short-circuit current density(J_(sc)),represent the great potential of solar radiation utilization,but suffer from the problem of increased interfacial charge recombination and reduced open-circuit voltage(V_(oc)).Herein,we report that an insertion of ultrathin Al_2O_3 layer(ca.1.2 A thickness)at the interface of ZnO nanowires(NWs)and Pb S quantum dots(QDs)could remarkably improve the performance of DBH-QDSCs fabricated from them,i.e.,an increase of V_(oc) from 449 mV to 572 mV,Jsc from21.90 mA/cm~2 to 23.98 mA/cm~2,and power conversion efficiency(PCE)from 4.29% to 6.11%.Such an improvement of device performance is ascribed to the significant reduction of the interfacial charge recombination rate,as evidenced by the light intensity dependence on Jsc and Voc,the prolonged electron lifetime,the lowered trap density,and the enlarged recombination activation energy.The present research therefore provides an effective interfacial engineering means to improving the overall performance of DBH-QDSCs,which might also be effective to other types of optoelectronic devices with large interface area.     

多频光栅物体高精度廓形三维测量及重建研究

针对目前实际系统中，由于噪声的存在，单频光栅逐点解相时无法获得全场相位值，导致对廓形复杂、体积小物体的重建精度低，提出多频结构光栅投影实现体积较小、形貌复杂物体的高精度重建。系统算法基于随时间序列变化改进的四步相移法对多频光栅进行解相，多频光栅解相是对每种频率的光栅单独展开相位，每种频率的光栅解相是逐点进行的，单频光栅中因噪声得到不连续的相位可通过其他频率光栅拟合修补，得到一个全场范围内连续的相位。经实验单频结构光测量体积小、形貌复杂物体的误差范围为0.1 mm～0.5 mm，而文中所提出方法精度达到了0.03 mm～0.05 mm，该方法精度提高了10倍左右。     

基于组合赋权法的我国CO_2排放量影响因素的评价研究

为客观和准确地挖掘和评价我国CO2排放量影响因素,选取技术投入、对外贸易开放程度、产业结构、能源消费结构、经济增长水平、人口规模和绿色植被用地面积等因素作为评价依据,构建我国CO2排放量影响因素指标体系。在此基础上,基于组合赋权法构建我国CO2排放量影响因素评价模型,实证分析2000~2011年我国CO2排放量影响因素。组合赋权法结果显示:技术投入、产业结构、能源消费结构、经济增长和绿色植被用地面积是影响我国CO2排放量的主要因素。组合赋权法在我国CO2排放量影响因素评价分析的运用,提高了评价的客观性和科学性,为进一步确定CO2排放量影响因素提供有价值的参考。