Impact of dopant-induced band tails on optical spectra, charge carrier transport, and dynamics in single-crystal CdTe.
Impact of dopant-induced band tails on optical spectra, charge carrier transport, and dynamics in single-crystal CdTe.
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DOI：
10.1038/s41598-022-16994-7
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发表时间：
2022-07-27
影响因子：
4.6
通讯作者：
Swain, Santosh K.
中科院分区：
文献类型：
--
作者：
Scajev, Patrik;Mekys, Algirdas;Subacius, Liudvikas;Stanionyte, Sandra;Kuciauskas, Darius;Lynn, Kelvin G.;Swain, Santosh K.
碲化镉（CdTe）半导体用于薄膜光电器件、探测器和其他光电应用。对于所有的技术，更高的效率和灵敏度实现减少电荷载流子复合。在这项研究中，我们使用国家的最先进的碲化镉单晶和电光测量开发的复合率依赖于激发和温度的碲化镉的详细了解。我们采用吸收，霍尔效应，时间分辨光致发光，和泵浦探测在80-600 K的温度范围内的高电阻率（未掺杂）和砷（As）掺杂的CdTe的复合和载流子动力学研究。我们报告了体未掺杂CdTe在低温下的超长寿命（30 µs）。载流子密度和迁移率的温度依赖性揭示了主要受主和施主的电离以及电离杂质的主导散射。我们还区分不同的重组缺陷。特别是，浅AsTe和深VCd-AsCd受体负责p型导电性。AX施主负责电子捕获，而非辐射复合中心（VCd-AsTe，As 2沉淀物）和本征缺陷（VCd-TeCd）分别在p型和n型CdTe中占主导地位。双分子和表面复合速率的温度依赖性也被揭示出来，双分子系数T−3/2温度依赖性和170 meV的有效表面势垒，导致在高温和激发下表面复合速度的增加。本研究的结果使我们能够得出结论，增强坩埚旋转生长的As掺杂的CdTe是有利的作为激活，导致更长的寿命和更大的迁移率和开路电压，由于较低的吸收和捕获。
Cadmium telluride (CdTe) semiconductors are used in thin-film photovoltaics, detectors, and other optoelectronic applications. For all technologies, higher efficiency and sensitivity are achieved with reduced charge carrier recombination. In this study, we use state-of-the-art CdTe single crystals and electro-optical measurements to develop a detailed understanding of recombination rate dependence on excitation and temperature in CdTe. We study recombination and carrier dynamics in high-resistivity (undoped) and arsenic (As)-doped CdTe by employing absorption, the Hall effect, time-resolved photoluminescence, and pump-probe in the 80–600 K temperature range. We report extraordinarily long lifetimes (30 µs) at low temperatures in bulk undoped CdTe. Temperature dependencies of carrier density and mobility reveal ionization of the main acceptors and donors as well as dominant scattering by ionized impurities. We also distinguish different recombination defects. In particular, shallow AsTe and deep VCd−AsCd acceptors were responsible for p-type conductivity. AX donors were responsible for electron capture, while nonradiative recombination centers (VCd−AsTe, As2 precipitates), and native defects (VCd−TeCd) were found to be dominant in p-type and n-type CdTe, respectively. Bimolecular and surface recombination rate temperature dependencies were also revealed, with bimolecular coefficient T−3/2 temperature dependence and 170 meV effective surface barrier, leading to an increase in surface recombination velocity at high temperatures and excitations. The results of this study allowed us to conclude that enhanced crucible rotation growth of As-doped CdTe is advantageous to As activation, leading to longer lifetimes and larger mobilities and open-circuit voltages due to lower absorption and trapping.
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影响因子：
4.6
作者：
McCandless BE;Buchanan WA;Thompson CP;Sriramagiri G;Lovelett RJ;Duenow J;Albin D;Jensen S;Colegrove E;Moseley J;Moutinho H;Harvey S;Al-Jassim M;Metzger WK
通讯作者：
Metzger WK
影响因子：
56.7
作者：
Li, Deng-Bing;Yao, Canglang;Yan, Feng
通讯作者：
Yan, Feng
影响因子：
3.2
作者：
Krasikov, D. N.;Scherbinin, A. V.;Sommerer, T. J.
通讯作者：
Sommerer, T. J.
影响因子：
6.9
作者：
Krasikov, Dmitry;Guo, Da;Sankin, Igor
通讯作者：
Sankin, Igor
影响因子：
3.2
作者：
Belas, E.;Uxa, S.;Bugar, M.
通讯作者：
Bugar, M.