Key Lab of Nanodevices and Applications, Suzhou Institute of Nano-Tech and Nano-Bionics, Chinese Academy of Sciences (CAS), Suzhou 215123, P. R. China.
University of Chinese Academy of Sciences, Beijing 100049, People's Republic of China.
Sci Rep. 2016 Nov 30;6:38044. doi: 10.1038/srep38044.
A six-volt vertically-stacked, high current GaAs photovoltaic power converter (PPC) has been designed and fabricated to produce output power over 1 W under monochromatic illumination. An N-GaAs/P-AlGaAs tunnel junctions (TJs) structure has been used for connecting each sub-cell in this vertically-stacked PPC device. The thickness of the each GaAs sub-cell has been derived based on the calculation of absorption depth of photons with a wavelength of 808 nm using absorption coefficient obtained from ellipsometry measurements. The devices were characterized under non-uniform CW laser illumination at 808 nm with incident power up to 4.1 W. A maximum conversion efficiency of 50.2% was achieved at 0.3 W under non-uniform (coupled in optical fiber) monochromatic illumination, dropping to 42.5% at 4.1 W. The operating voltage at the maximum power point is 5.5-6.0 V, depending on the incident laser power, and an output electrical power output of 1.3 W can be extracted at a laser power of 2.9 W and the maximum electrical power output amounts to 1.72 W. The external quantum efficiency (EQE) measurement indicates that the performance of PPC can be further improved by refining the design of the thickness of sub-cells and improving TJs.
已设计并制造出一种六伏垂直堆叠、高电流砷化镓光伏功率转换器 (PPC)，可在单色照明下产生超过 1 瓦的输出功率。为了连接这种垂直堆叠 PPC 器件中的每个子电池，使用了 N-GaAs/P-AlGaAs 隧道结 (TJ) 结构。根据使用椭圆光度法测量得到的吸收系数计算出 808nm 波长光子的吸收深度，得出了每个 GaAs 子电池的厚度。在非均匀连续波激光照射下，器件在 808nm 下的功率高达 4.1W 时进行了特性测试。在非均匀（通过光纤耦合）单色照明下，在 0.3W 时实现了 50.2%的最大转换效率，在 4.1W 时降至 42.5%。最大功率点的工作电压为 5.5-6.0V，具体取决于入射激光功率，在 2.9W 的激光功率下可提取 1.3W 的输出电功率，最大电功率输出高达 1.72W。外量子效率 (EQE) 测量表明，通过细化子电池厚度的设计和改进 TJ，可以进一步提高 PPC 的性能。
