高速沉积本征微晶硅的优化及其在太阳电池中的应用  

Optimization of high rate growth high quality μc-Si:H thin films and its application to the solar cells

作　　者：韩晓艳[1] 侯国付[1] 魏长春[1] 张晓丹[1] 戴志华[1] 李贵君[1] 孙建[1] 陈新亮[1] 张德坤[1] 薛俊明[1] 赵颖[1] 耿新华[1] 

机构地区：[1]南开大学光电子薄膜器件与技术研究所,光电子薄膜器件与技术天津市重点实验室,光电信息技术科学教育部重点实验室,天津300071

出　　处：《物理学报》2009年第6期4254-4259,共6页Acta Physica Sinica

基　　金：国家重点基础研究发展计划(批准号:2006CB202602,2006CB202603);国家自然科学基金(批准号:60506003);国家科技计划配套项目(批准号:07QTPTJC29500);天津市应用基础研究计划(批准号:07JCYBJC04000)资助的课题~~

摘　　要：采用高压高功率的甚高频等离子体增强化学气相沉积(VHF-PECVD)技术高速(沉积速率约为1.2nm/s)沉积了一系列不同厚度的本征微晶硅薄膜,并通过Raman谱和XRD谱的测试,研究了高速沉积时本征微晶硅薄膜的微结构演变特性及其对电池性能的影响.针对其微结构特性及高速沉积本身存在的离子轰击作用强的特点,提出了在沉积微晶硅薄膜过程中采用功率梯度的方法,达到有效地控制薄膜微结构变化的目的,并在一定功率梯度范围内降低了电子温度,提高了薄膜质量,从而使电池效率明显提高.最后在沉积速率为1.2nm/s时,制备得到光电转换效率为9.36%的单结微晶硅太阳电池,将其应用到叠层电池中制备得到效率为11.14%的非晶硅/微晶硅叠层电池.A series of high rate growth uc-Si： H thin films with different thicknesses were deposited by very high frequency plasma enhanced chemical vapor deposition （VHF-PECVD） process with high power and high pressure. The microstructure of the uc-Si： H thin films was studied by the Raman and XRD spectra. It was found that the crystal fraction and grain size increased with the thickness of the thin film when the thickness was less than 1000 nm, and then came to saturation when the thickness was higher than 1000 nm. However, the performance of solar cells decreased obviously when the thickness increased from 1000 nm to 2000 nm. Considering the microstructure properties and the ion bombardment during the high rate process, we investigated the controlled microstructure evolution and the improved material quality by discharge power profiling, which improved the performance of solar cells. By optimizing the profiling parameters, such as the amount and the rate of change in discharge power, a high efficiency of 9.36 % was obtained with an i-layer deposition rate of 1.2 nm/s. Furthermore, we used the improved uc-Si： H cell in an a-Si： H/uc-Si： H double-junction structure and achieved an initial active-area cell efficiency of 11.14% .

关 键 词：高速沉积 微晶硅薄膜 微结构演变 功率梯度 

分 类 号：TM914.4[电气工程—电力电子与电力传动]