Low-cost multijunction photovoltaic devices are the next step in the solar energy revolution. Adding a bottom junction with a low bandgap energy material through plasma enhanced chemical vapor deposition (PECVD) processing could potentially provide a low-cost boost in conversion efficiency. A logical candidate for this low bandgap material is germanium. In this work we investigate the growth of PECVD processed hydrogenated amorphous/nano-crystalline germanium (a/nc-Ge:H), by characterizing over 100 samples, processed with a wide range of deposition pressures, powers, temperatures and GeH₄ dilution in hydrogen, using elemental analysis, vibrational analysis and analysis of the opto-electrical properties. We have identified a small processing window in which nc-Ge:H films are processed reproducibly. We also report on the strong correlation between the refractive index of the films and the presence- and extent of post-deposition oxidation. Notably, the oxidation generally increased the photoresponse of the films, as it results in a decrease of room temperature ${\sigma }_{\text{d}}$ by 1-3 orders of magnitude. However, oxidation results in an increase of the bandgap energy and therefore impedes the development of a low bandgap material. The lowest $E_{\text{04}}$ we report is about 1.1eV, with an $E_{\text{Tauc}}$ of 0.9eV and an ${\sigma }_{\text{ph}}$/${\sigma }_{\text{d}}$ of 3.4.

低成本多结光伏器件是太阳能革命的下一步。通过等离子增强化学气相沉积（PECVD）处理添加具有低带隙能量材料的底部结可能会以低成本提高转换效率。这种低带隙材料的合理选择是锗。在这项工作中，我们通过表征100多种样品，用各种沉积压力，功率，温度和GeH ₄处理，研究了PECVD处理的氢化非晶/纳米晶锗（a / nc-Ge：H）的生长。在氢中稀释，使用元素分析，振动分析和光电性能分析。我们确定了一个小的加工窗口，在该窗口中可重复加工nc-Ge：H薄膜。我们还报道了薄膜的折射率与沉积后氧化的存在和程度之间的强相关性。值得注意的是，氧化通常会增加薄膜的光响应性，因为这会导致室温降低${\sigma }_{\text{d}}$减少1-3个数量级。然而，氧化导致带隙能量的增加，因此阻碍了低带隙材料的发展。最低的${Ë}_{\text{04}}$ 我们报告约为1.1eV， ${Ë}_{\text{陶克}}$ 0.9eV和 ${\sigma }_{\text{ph值}}$/${\sigma }_{\text{d}}$ 的3.4。