We present an inverted metamorphic rear heterojunction ∼1.0 eV GaInAs solar cell deposited by dynamic hydride vapor phase epitaxy (D-HVPE) with high growth rate. This device uses a Ga_1−xIn_xP compositionally graded buffer (CGB) to bridge the lattice constant gap between the GaAs substrate and the Ga_0.71In_0.29As emitter layer. High-resolution x-ray diffraction and transmission electron microscopy confirm that the Ga_0.71In_0.29As emitter is grown lattice-matched to the in-plane lattice constant of the CGB with minimal generation of defects at the GaInAs/GaInP interface. The device contains a threading dislocation density of 2.3 × 10⁶ cm⁻², a level that enables high-performance minority carrier devices and is comparable to previously demonstrated GaInP CGBs grown by D-HVPE. The device exhibits an open-circuit voltage of 0.589 V under a one-sun AM1.5G illumination condition and a bandgap-voltage offset of 0.407 V, indicating metamorphic epitaxial performance nearly equal to state-of-the-art devices. We analyze the dark current of the device and determine that reducing recombination in the depletion region, which can be achieved by reducing the threading dislocation density and optimizing the device doping density, will improve the device performance. The CGB and device layers, comprising ∼8 μm of thickness, are grown in under 10 min, highlighting the ability of D-HVPE to produce high-quality metamorphic devices of all types with the potential for dramatically higher throughput compared to present technology.

中文翻译：

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通过动态氢化物气相外延生长的倒变质 GaInAs 太阳能电池

我们提出了一种通过动态氢化物气相外延 (D-HVPE) 沉积的具有高生长速率的倒变质背面异质结 ~1.0 eV GaInAs 太阳能电池。该器件使用 Ga _1-x In _x P 成分渐变缓冲液 (CGB) 来桥接 GaAs 衬底和 Ga _0.71 In _0.29 As 发射极层之间的晶格常数间隙。高分辨率 X 射线衍射和透射电子显微镜证实 Ga _0.71 In _0.29 As 发射极与 CGB 的面内晶格常数晶格匹配，在 GaInAs/GaInP 界面产生的缺陷最少。该器件包含2.3 × 10 ⁶  cm ^-2的穿透位错密度，该级别可实现高性能少数载流子器件，并且可与之前演示的 D-HVPE 生长的 GaInP CGB 相媲美。该器件在单太阳 AM1.5G 光照条件下的开路电压为 0.589 V，带隙电压偏移为 0.407 V，表明变质外延性能几乎与最先进的器件相当。我们分析了器件的暗电流，并确定减少耗尽区的复合可以通过降低穿透位错密度和优化器件掺杂密度来实现，从而提高器件性能。CGB 和器件层，包括 ∼8  μm 的厚度，在 10 分钟内生长，突出了 D-HVPE 生产所有类型的高质量变质器件的能力，与现有技术相比，具有显着更高的吞吐量的潜力。