Suppressed auger recombination in "giant" nanocrystals boosts optical gain performance.
Suppressed auger recombination in "giant" nanocrystals boosts optical gain performance.
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DOI：
10.1021/nl901681d
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发表时间：
2009-10
期刊：
影响因子：
10.8
通讯作者：
Klimov VI
中科院分区：
文献类型：
--
作者：
García-Santamaría F;Chen Y;Vela J;Schaller RD;Hollingsworth JA;Klimov VI
半导体纳米晶体的许多潜在应用受到非辐射俄歇复合的阻碍，其中电子-空穴（激子）复合能量被转移到第三个电荷载流子。这一过程严重限制了光学增益的寿命和带宽，导致发光二极管和光伏电池产生大量非辐射损耗，并被认为是造成单纳米晶体发射间歇性（“闪烁”）的原因。抑制俄歇复合的纳米结构的发展最近成为胶体纳米晶体领域许多研究的主题。在这里，我们提供了直接的实验证据，证明由小的 CdSe 核和厚的 CdS 壳组成的所谓“巨型”纳米晶体对俄歇衰变率表现出显着（数量级）的抑制。因此，即使是非常高阶的多激子也表现出显着的发射效率，这使我们能够展示具有极大带宽（> 500 meV）的光学放大并记录低激发阈值。该演示代表了利用可溶液加工的胶体纳米粒子的实用激光技术的一个重要里程碑。
Many potential applications of semiconductor nanocrystals are hindered by nonradiative Auger recombination wherein the electron–hole (exciton) recombination energy is transferred to a third charge carrier. This process severely limits the lifetime and bandwidth of optical gain, leads to large nonradiative losses in light-emitting diodes and photovoltaic cells, and is believed to be responsible for intermittency (“blinking”) of emission from single nanocrystals. The development of nanostructures in which Auger recombination is suppressed has recently been the subject of much research in the colloidal nanocrystal field. Here, we provide direct experimental evidence that so-called “giant” nanocrystals consisting of a small CdSe core and a thick CdS shell exhibit a significant (orders of magnitude) suppression of Auger decay rates. As a consequence, even multiexcitons of a very high order exhibit significant emission efficiencies, which allows us to demonstrate optical amplification with an extraordinarily large bandwidth (>500 meV) and record low excitation thresholds. This demonstration represents an important milestone toward practical lasing technologies utilizing solution-processable colloidal nanoparticles.
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DOI：
10.1016/s1386-9477(02)00374-0
发表时间：
2002-04-01
影响因子：
3.3
作者：
Nozik, AJ
通讯作者：
Nozik, AJ
影响因子：
4
作者：
Chan, Y;Caruge, JM;Bawendi, MG
通讯作者：
Bawendi, MG
影响因子：
3.7
作者：
Klimov, V. I.;McGuire, J. A.;Rupasov, V. I.
通讯作者：
Rupasov, V. I.
影响因子：
56.9
作者：
Klimov, VI;Mikhailovsky, AA;Bawendi, MG
通讯作者：
Bawendi, MG
影响因子：
8.6
作者：
Liu, N;Tersoff, J;Shih, CK
通讯作者：
Shih, CK