A stacked chalcopyrite thin‐film tandem solar cell with 1.2 V open‐circuit voltage

CuGaSe₂ (CGS) thin films were prepared on tin‐doped indium oxide (ITO) coated soda‐lime glass substrates by thermal co‐evaporation to fabricate transparent solar cells. The films consisted of columnar grains with a diameter of approximately 1 μm. Some deterioration of the transparency of the ITO was observed after deposition of the CGS film. The CGS solar cells were electrically connected in series with Cu(In,Ga)Se₂ (CIGS) solar cells and mechanically stacked on the CIGS cells to construct tandem cells. The tandem solar cell with the CGS cell as the top cell showed an efficiency of 7.4% and an open‐circuit voltage of 1.18 V (AM 1.5, total area). Copyright © 2003 John Wiley & Sons, Ltd.     

In和Te掺杂PbSe薄膜制备及其对薄膜光电性能的影响机制

采用中频磁控溅射技术制备了PbSeIn和PbSeTe两种掺杂PbSe薄膜, 并采用理论模拟与实际实验相结合的方法研究了In和Te两种元素的掺杂机制及其对薄膜性 能的影响。结果表明,In原子主要通过置换Pb原子的形式进行掺杂,而Te原子则主要置换 Se原子;与未掺杂PbSe薄膜相比,PbSeIn和PbSeTe两种薄膜的光电敏感性均有一定提高, 其中In掺杂PbSe薄膜的平均电阻变化率最高。这是由于In元素在PbSe薄膜禁带内形成深杂 质能级,提高非平衡载流子寿命所导致的。而PbSeTe薄膜的光电敏感性则与未掺杂PbSe薄 膜相近。     

新型MOS氧化层TiO_2薄膜

采用低压MOCVD法在(111)取向硅基上制备了TiO2薄膜代替通常MOS结构的SiO2,并测量了TiO2薄膜的介电常数、表面固定电荷密度和电阻率,与SiO2作比较,结果表明:TiO2的MOS结构比SiO2具有更优良的性质,更适应于超大规模集成电路制造。     

喇曼光谱研究硅烷体积分数对Si薄膜结构影响

采用等离子体增强化学气相沉积(PECVD)技术,在一定射频功率、衬底温度和气压下,在普通玻璃衬底上制备了不同硅烷体积分数的Si薄膜材料.使用喇曼光谱对薄膜材料的结构进行了研究.结果表明,随着硅烷体积分数的降低,Si薄膜沉积速率将会逐渐降低.当硅烷体积分数降到2%时,喇曼光谱检测到出现对应的晶体Si的吸收峰,而最初的非晶吸收峰位逐渐减弱.Si薄膜的结构实现了由非晶向微晶转变.随着硅烷体积分数进一步降低,结晶率不断提高,微晶比例进一步扩大.     

具有新型电荷产生层的叠层有机发光器件

研究了采用薄层WO3作为叠层有机发光器件电荷产生层时的性能并对其厚度进行了优化,器件的电荷产生层由Li掺杂的电子注入层和高透明的WO3组成.研究表明,薄层WO3具有很高的透明度,并能有效地产生和注入空穴.叠层器件性能与单发光单元器件相比较,其亮度及效率均有大幅提高,叠层器件的最大电流效率达到了4.2 cd/A,在相同的电流密度下,叠层器件的效率约为传统器件的2倍;同时,电荷产生层的性能与WO3薄膜厚度密切相关,WO3薄膜厚度为3 nm时,器件的效率在整个电流范围内都保持稳定.采用薄层WO3作为电荷产生层为制备高效叠层有机发光器件提供了一条有效的途径.     

厚膜熔断器的电气特性模拟

利用ANSYS软件建立了高性能厚膜熔断器的有限元模型,并对其在正常工作状态下的瞬态温度场变化过程进行了数值模拟,得到熔断器引脚温升为65.30℃,电阻为0.05719Ω,发热功率为0.91504W等参数,并进行了实验验证。结果表明:实验和数值模拟的误差率为3.00%~4.00%,为熔断器的设计制造提供了方法和理论依据。     

sol-gel法制备WO3电致变色薄膜的研究

采用正交实验设计方法,优化了钨粉过氧化聚钨酸sol-gel法制备WO3薄膜的配方,并且通过测定薄膜的物相结构、光透过率和循环伏安特性等研究了薄膜的电致变色性能。结果表明,制备WO3薄膜的最优配方为:钨粉(纯度为99.5%)6g、浓双氧水20mL、无水乙醇22mL、冰醋酸6mL。该配方所制备的薄膜具有非晶态结构,且薄膜在着色态、褪色态下的透过率之差达到50%以上。     

一种新颖的聚合物分散液晶反射光栅

在制备液晶光开关的基础上,采用聚合物分散液晶(PDLC)与金属反射光栅压合的方法研制了一种新型反射式液晶光栅器件,并对其响应时间、调制电压、不同偏振态和不同入射角情况下的衍射效率等光电参数进行了测试.结果表明,该液晶反射光栅具有电场可调性,当驱动电压小于特定值时仅观察到常规反射现象,当驱动电压大于40 V时器件出现明显的光栅衍射效应,且1级衍射效率最大可到6.7%.实验讨论了入射光的偏振态、入射角度等因素对PDLC光栅衍射效率的影响,同时测试了该液晶反射光栅的电场响应时间为10 ms.     

PDLC膜的电光特性实验

设计对面／共面两用电极,制备聚合物分散液晶（PDLC）膜样品,用偏光显微镜观察液晶微滴形态,在不加电场的关态测试雾度,在施加电场的开态测试透光率随电压变化的电光特性。实验测得雾度约为H=93％,对面电板电场下透光率最大约为T=84％,共面电极电场下透光率最大约为T=82％。对PDLC膜电光特性给出新的认识。     

Optical and structural properties of sol-gel derived nanostructured CeO_2 film

Sol-gel derived nanostructured CeO2 film was deposited on glass substrate using the dip-coating technique with annealed at 650oC. X-ray diffraction (XRD), scanning electron microscopy (SEM), Fourier transform infrared (FTIR), UV/VIS and photoluminescence (PL) spectroscopy studies were employed to analyze the structural and optical properties of the sol-gel derived nanostructured CeO2 film. The average crystallite size was estimated from XRD pattern using Scherrer equation as about 3–4 nm. SEM micrograph shows the film have good adherence to the substrate, porous in nature and crack free. The UV-visible absorption spectroscopic measurement results showed that the products had conspicuous quantum size effects. The absorption spectrum indicates that the sol-gel derived nanostructured CeO2 film have a direct bandgap of 3.23 eV and the photoluminescence spectra of the film show strong band at 378 nm may have promising applications as optoelectronic materials.