基于光子增强热电子发射（PETE）机理太阳能电池器件研究

发布时间：2018-06-08 12:47

本文选题：PETE器件 + 阴极　；参考：《中国科学院研究生院（西安光学精密机械研究所）》2014年博士论文

【摘要】：基于光子增强热电子发射(PETE)效应太阳能利用是近年国际上提出的一种新型宽光谱太阳能综合利用方式,PETE太阳能发电方式理论上能够实现聚光技术、光伏发电技术以及光热发电技术的高效结合,系统复合利用理论效率可达到50%以上。目前,对于PETE太阳能电池器件的研究还不完善和深入,此前关于PETE太阳能利用的研究,都停留在理论研究方面。对于PETE器件的设计和研制暂未见有报到。本论文基于建立和完善的PETE器件理论模型,给出了基于PETE器件优化参数的高效太阳能电池系统集成方案,实现了基于GaAs透射式阴极的PETE器件制作,完成了基于PETE效应的太阳能电池集成系统的太阳能光伏／光热复合利用技术论证,为系统深入开展PETE光伏／光热复合利用系统研究奠定良好基础,具体研究内容如下。一、基于PETE器件理论模型的建立,开展了影响器件转换效率的阴阳极材料特性研究,并对PETE器件关键参数进行了优化设计。通过研究对比多种耐高温光电发射材料特性,选择砷化镓材料作为器件高效PETE阴极；引入砷化镓阴极指数梯度掺杂结构提高阴极电子输运能力,提高了器件阴极光子增强热电子发射效率；基于PETE光电／光热复合电池系统能量传递过程和系统转换效率的分析,在聚光比200倍,阴极工作温度1000K设计条件下,系统总效率可以达到25%,其中PETE器件的效率为20%。二、基于透射式PETE器件的结构与制作工艺的设计,完成了PETE器件的研制。通过MOCVD外延生长技术,制备了高质量GaAs热光电阴极PETE发射材料指数掺杂结构；通过GaAs电场诱导PETE发射实验,验证了外延GaAs材料具有良好的PETE发射特性；利用热丝CVD法,在硅(Si)基底上制备了功函数为1.1eV的阳极金刚石薄膜材料；通过玻璃基底阴极欧姆接触处理工艺和真空光电管封装技术,完成了PETE器件真空封接；在高真空光电阴极光电特性测量系统中,对器件阴极进行了Cs激活处理工艺,在400℃时测得器件可见光范围内光谱灵敏密度为200mA/W;计算得器件太阳能光子PETE转化效率为10%,符合PETE器件400-C时的转化效率理论值。三、设计了PETE太阳能光电／光热复合利用系统集成方案,开展了PETE太阳能光电／光热复合发电实验研究。复合电池系统在64倍模拟太阳光聚光条件下,PETE器件阴极工作温度为600K, PETE器件系统转换效率为1.5%；通过器件表面防热量流失处理,能够明显改善PETE器件实验效果,若复合电池系统在标准日光照条件下,系统聚光比为200倍,PETE阴极工作温度可以接近1000K,器件系统转换效率能够达到15%。四、开展了反射式PETE器件可行性分析,并利用飞秒激光加工太阳能电池材料技术,开展了反射式PETE器件阴极表面“陷光”微结构增强太阳光吸收探索性实验研究。本论文紧跟国际太阳能复合利用研究前沿,在斯坦福大学提出的基于太阳光增强吸收热电子发射的PETE原理的太阳能复合利用思想上,就PETE太阳能能量转换理论模型的建立、PETE器件的设计与制作以及基于PETE效应的太阳能电池集成系统的光电/光伏复合转换效率分析三个方面展开理论和实验研究。对比国内外目前PETE太阳能利用研究,国际上尚无研究报导的工作创新点如下：一、建立了PETE阴极电子扩散-发射模型,并对PETE器件的太阳能转换过程进行分析,提出了通过指数掺杂方式提高PETE器件阴极转换效率的方式。二、对透射式PETE器件结构和制作流程进行了设计,并利用光电器件真空封装技术实现PETE能量转换器件阴阳极真空近贴结构,有效克服了现有光伏电池pn节升温而导致电池失效的问题。三、结合聚光技术,光子增强热电子发射原理(PETE)和基于Seebeck效应的热电发电技术,在理论研究基础上实现了光电／光热太阳能复合高效利用原理实验验证,并进行了集成系统效率分析。
[Abstract]:The solar energy utilization based on the photon enhanced thermal electron emission (PETE) effect is a new type of wide spectral solar comprehensive utilization in recent years. The PETE solar power generation mode can theoretically realize the light gathering technology, the photovoltaic power technology and the high efficiency combination of the optical and thermal power generation technology, and the theoretical efficiency of the system compound utilization can reach 50%. At present, the research on PETE solar cell devices is not perfect and deep. The previous research on the utilization of PETE solar energy has stayed in the theoretical research. The design and development of PETE devices have not been reported. Based on the establishment and improvement of the theoretical model of PETE devices, the optimization parameters based on PETE devices are given high. The integrated scheme of solar cell system has realized the production of PETE devices based on GaAs transmission cathodes, and completed the demonstration of solar photovoltaic / photothermal composite utilization technology based on the PETE effect based solar cell integration system. It lays a good foundation for the research of the system in which the PETE photovoltaic / light heat compound system is deeply carried out and the specific research content is studied. As follows.
Firstly, based on the establishment of the theoretical model of PETE device, the characteristics of the cathode and yang material affecting the conversion efficiency of the device are carried out, and the key parameters of the PETE device are optimized. By studying and comparing the characteristics of a variety of high temperature photoemission materials, gallium arsenide materials are selected as the efficient PETE cathode of the device, and the exponential gradient of the gallium arsenide cathode is introduced. The doping structure improves the cathodic electron transport capacity and improves the efficiency of the photocathode enhanced Thermo Electron emission. Based on the analysis of the energy transfer process and the system conversion efficiency of the PETE photoelectric / photothermal composite battery system, the total efficiency of the system can reach 25% under the 200 times of the concentration ratio and the design of the cathode working temperature 1000K, of which the PETE device is used. The efficiency is 20%.
Two, based on the design of the structure and fabrication process of transmission PETE devices, the development of PETE devices was completed. The exponential doping structure of high quality GaAs thermo photocathode PETE emitting materials was prepared by MOCVD epitaxial growth technology. The good PETE emission characteristics of the outer GaAs material were verified by the GaAs field induced PETE emission experiment. The anode diamond film materials with function function of 1.1eV were prepared on silicon (Si) substrate by hot wire CVD method. Vacuum sealing of PETE devices was completed through the ohm contact processing technology of glass substrate cathode and vacuum phototube packaging technology, and the Cs activation treatment of the cathode was carried out in the high vacuum photocathode photoelectric characteristic measurement system. The sensitive density of the spectrum in the visible light range of the device was 200mA/W at 400 C, and the conversion efficiency of the solar photon PETE was calculated to be 10%, which accords with the theoretical value of the conversion efficiency of the PETE device 400-C.
Three, the integrated scheme of PETE solar optoelectronic / photothermal composite utilization system is designed, and the experimental study of PETE solar photovoltaic / photothermal composite power generation is carried out. Under the condition of 64 times the simulation of solar light, the working temperature of the PETE device is 600K, the conversion efficiency of the PETE device system is 1.5%, and the loss of heat loss on the surface of the device is carried out. Treatment can obviously improve the experimental results of PETE devices. If the composite battery system is under standard sunlight conditions, the concentration ratio of the system is 200 times, the working temperature of the PETE cathode can be close to 1000K, and the conversion efficiency of the device system can reach 15%..
Four, the feasibility analysis of the reflective PETE device is carried out, and the experimental research on the enhancement of the solar absorption by the "trapping" micro structure of the cathode surface of the reflective PETE device is carried out by using the femtosecond laser to process the solar cell material technology.
This paper follows the international research frontier of solar energy compound utilization. In Stanford University, the theory of solar energy conversion based on the PETE principle of solar light enhancement absorption thermal electron emission is based on the establishment of the theoretical model of PETE solar energy conversion, the design and production of PETE devices and the solar cell integration system based on the PETE effect. The theoretical and Experimental Research on the three aspects of the photoelectric / photovoltaic composite conversion efficiency analysis are carried out. Compared with the current research on PETE solar utilization at home and abroad, there are no research reports in the world as follows:
First, the PETE cathode electron diffusion emission model is established, and the solar energy conversion process of the PETE device is analyzed. The method of improving the cathodic conversion efficiency of the PETE device by exponential doping is proposed.
Two, the structure and process of the transmission PETE device are designed, and the vacuum packaging technology of the optoelectronic devices is used to realize the near post structure of the cathode and Yang vacuum of the PETE energy converter, which effectively overcomes the problem of the battery failure caused by the heating up of the existing photovoltaic cell PN nodes.
Three, on the basis of theoretical research, the experimental verification of the principle of photoelectric / photothermal solar compound efficient utilization is realized and the efficiency analysis of integrated system is carried out based on the theory of PETE and Seebeck effect based thermoelectric power generation technology.
【学位授予单位】：中国科学院研究生院（西安光学精密机械研究所）
【学位级别】：博士
【学位授予年份】：2014
【分类号】：TM914.4

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