Department of Chemistry, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
ACS Nano. 2011 Jul 26;5(7):5566-71. doi: 10.1021/nn2010238. Epub 2011 May 24.
A colloidal quantum dot (QD) luminescent down-shifting (LDS) layer is used to sensitize an InGaAs short wavelength infrared photodetector to the near UV spectral band. An average improvement in the external quantum efficiency (EQE) from 1.8% to 21% across the near UV is realized using an LDS layer consisting of PbS/CdS core/shell QDs embedded in PMMA. A simple model is used to fit the experimental EQE data. A UV sensitive InGaAs imaging array is demonstrated and the effect of the LDS layer on the optical resolution is calculated. The bandwidth of the LDS detector under UV illumination is characterized and shown to be determined by the photoluminescence lifetime of the QDs.
使用胶体量子点（QD）发光下转换（LDS）层将 InGaAs 短波长红外光电探测器敏化到近紫外光谱带。使用由嵌入 PMMA 的 PbS/CdS 核/壳 QD 组成的 LDS 层，在近紫外光下实现了平均外量子效率（EQE）从 1.8%到 21%的提高。使用简单的模型拟合实验 EQE 数据。演示了一个 UV 敏感的 InGaAs 成像阵列，并计算了 LDS 层对光学分辨率的影响。在 UV 照明下，LDS 探测器的带宽特性，并表明其由 QD 的光致发光寿命决定。
