Electroluminescence from nanocrystals above 2 µm

Abstract

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Guided-Mode Resonator Coupled with Nanocrystal Intraband Absorption

“…Then, the electron cools from 1P e to 1S e (end of regime I); this relaxation time τ P→S has been found to be 3.5 ps. This duration is in line with the intraband relaxation dynamics in CdSe or HgTe − nanocrystals for which the relaxation decay is found to be in a 1–10 ps range . Note that in the case of pristine HgTe, only a negative signal is observed (middle panel of Figure a).…”

Mid-infrared HgTe Colloidal Quantum Dot LEDs

“…For the short-wave device, Figure 2c shows that the EQE peaks around 5 V at around 2.2 × 10 −3 and drops little over a bias range of 5 to 12 V. The EL EQE at 2.5 μm of 2.2 × 10 −3 is similar to the one reported for ZnO/HgTe heterostructures by Qu and coworkers for 2.3 μm emission. 22 For the mid-wave device, Figure 2d shows that the mid-IR EL EQE peaks at low bias with 1.0 × 10 −3 at 2 V bias and drops by half at 8 V.…”

“…This device emitted at 1.6 μm with a maximum EQE of 2 × 10 –4 . Bossavit and co-workers made QLEDs using a ZnO/HgTe heterojunction, achieving maximum EQE 2.2% at 1.2 μm with a turn-on voltage of 0.8 V, − and the emission was extended to 2.3 μm with an EQE of 3 × 10 –3 . Emission in the mid-IR is fundamentally more challenging because radiative rates slow down while nonradiative processes speed up.…”

Photoconductive focal plane array based on HgTe quantum dots for fast and cost-effective short-wave infrared imaging

“…Colloidal quantum dots (QDs) now offer an interesting alternative. 2 Over the past two decades, a lot of efforts have been dedicated, first to push their absorption toward longer wavelengths 3–5 and later to integrate them into functional devices such as LEDs, 6–9 solar cells 10 and IR sensors. 2,11–14 For the latter application, most of the efforts have been focused on the design of single pixel devices, but there are few reports relative to image sensors.…”

“…Colloidal quantum dots (QDs) now offer an interesting alternative. 2 Over the past two decades, a lot of efforts have been dedicated, first to push their absorption toward longer wavelengths [3][4][5] and later to integrate them into functional devices such as LEDs, [6][7][8][9] solar cells 10 and IR sensors. 2,[11][12][13][14] For the latter application, most of the efforts † Electronic supplementary information (ESI) available: Ellipsometric measurements, simulation of the electric field and current density distribution, additional data relative to EQE determination, imaging at high frame rate, procedure for image correction, additional infrared imaging using band pass filters.…”