论文标题
来自GAAS底物的单晶III-V太阳能电池的脉冲激光射出
Pulsed Laser Ejection of Single-Crystalline III-V Solar Cells From GaAs Substrates
论文作者
论文摘要
像许多光电子一样，最高质量的III-V太阳能电池是GAAS基板上的薄单晶多层。将这些设备层与它们的增长底物分开，可实现更高的性能设备和晶圆的再利用，这两者对于地面市场中的III-V太阳能细胞生存能力至关重要。在这里，我们使用10 ns使用10 ns，未关注的nd：yag laser pulse删除了牢固的键合，晶格匹配，16毫米$^2 $ x 3.5 um GAAS设备。该脉冲在设备下方的下型，晶格匹配的，结晶层中选择性吸收，驱动一个准二维烧蚀事件，该事件从底物中弹出了晶体多层。经过几分钟的选择性湿化学蚀刻和前触点沉积后，我们的冠军0.1 cm $^2 $设备显示（17.4 +/- 0.5）％的功率转换效率和1.07 V的开路电压为1.07 V，使用AM1.5 Direct（1000 W M $^{-2} $），没有抗反重涂层。我们表明，性能与通过常规底物溶解过程产生的类似太阳能电池相媲美。我们讨论独特的过程特征和机会，例如每个激光脉冲分离晶片大小的薄膜太阳能电池的潜力。
Like many optoelectronics, the highest quality III-V solar cells start out as thin single-crystalline multilayers on GaAs substrates. Separating these device layers from their growth substrate enables higher performing devices and wafer reuse, both of which are critical for III-V solar cell viability in a terrestrial market. Here, we remove rigidly-bonded, lattice-matched, 16 mm$^2$ x 3.5 um thick GaAs devices off a GaAs substrate using a 10 ns, unfocused Nd:YAG laser pulse. The pulse is selectively absorbed in a lower-bandgap, lattice-matched, crystalline layer below the device, driving a quasi-two dimensional ablation event that ejects the crystalline multilayer from the substrate. After minutes of selective wet-chemical etching and front contact deposition, our champion 0.1 cm$^2$ device showed a (17.4 +/- 0.5) % power conversion efficiency and an open-circuit voltage of 1.07 V, using AM1.5 direct (1000 W m$^{-2}$) with no anti-reflection coating. We show that the performance is comparable to similar solar cells produced via conventional substrate dissolution processes. We discuss unique process characteristics and opportunities, such as the potential to separate wafer-sized thin film solar cells per laser pulse.
