Photocurrent of 1 eV GaInNAs lattice-matched to GaAs
Photocurrent of 1 eV GaInNAs lattice-matched to GaAs
复制标题
DOI：
10.1016/s0022-0248(98)00563-6
复制
发表时间：
1998-12-01
影响因子：
1.8
通讯作者：
Keyes, BM
中科院分区：
文献类型：
--
作者：
Geisz, JF;Friedman, DJ;Keyes, BM
已在电化学电池中测量了与带隙为 1 eV 的 GaAs 晶格匹配的 GaInNAs 的光谱光电流响应或量子效率，以优化用于与 GaAs 或 Ge 晶格匹配的多结太阳能电池的材料质量。使用二甲基肼作为氮源通过MOVPE生长的含约3%氮的GaInNA被发现是p型的，空穴浓度约为1 x 10(17) cm(-3)，这可能是由于SIMS观察到的无意的碳掺杂所致。这种无意掺杂的材料通常具有高达 20% 的内量子效率和约 10000 cm(-1)、比带边高 200 meV 的吸收系数。通过在材料中掺杂 Si、Se 或 Zn，我们发现量子效率与载流子浓度密切相关，因为量子效率受到结耗尽宽度而不是体少数载流子扩散长度的限制。低少数载流子寿命和迁移率似乎都是造成这些短扩散长度的原因。我们观察到由于生长条件和生长后退火的变化，温度依赖性霍尔迁移率和光致发光强度显着增加。 (C) 1998 Elsevier Science B.V. 保留所有权利。
The spectral photocurrent response, or quantum efficiency, of GaInNAs lattice-matched to GaAs with a bandgap of 1 eV has been measured in an electrochemical cell in order to optimize material quality for use in a multijunction solar cell lattice-matched to GaAs or Ge. GaInNAs with about 3% nitrogen grown by MOVPE using dimethylhydrazine as a nitrogen source was found to be p-type with hole concentrations of about 1 x 10(17) cm(-3), possibly due to unintentional carbon doping as observed by SIMS. This unintentionally doped material typically had up to 20% internal quantum efficiencies and an absorption coefficient of about 10000 cm(-1), 200 meV above the bandedge. By doping the material with Si, Se, or Zn, we find that the quantum efficiency is strongly correlated with the carrier concentration because the quantum efficiency is limited by the junction depletion width rather than the bulk minority carrier diffusion length. Low minority carrier lifetimes and mobilities both appear to contribute to these short diffusion lengths. We have observed significant increases in temperature dependent Hall mobilities and photoluminescence intensities due to changes in growth conditions and post-growth anneals. (C) 1998 Elsevier Science B.V. All rights reserved.