Single Nanocrystal Spectroscopy of Shortwave Infrared Emitters

Abstract

Short-wave infrared (SWIR) emitters are at the center of ground-breaking applications in biomedical imaging, next-generation optoelectronic devices, and optical communications. Colloidal nanocrystals based on indium arsenide are some of the most promising SWIR emitters to date. However, the lack of single-particle spectroscopic methods accessible in the SWIR has prevented advances in both nanocrystal synthesis and fundamental characterization of emitters. Here, we demonstrate an implementation of a solution photon correlation Fourier spectroscopy (s-PCFS) experiment utilizing the SWIR sensitivity and time resolution of superconducting nanowire single-photon detectors to extract single-particle emission linewidths from colloidal indium arsenide/cadmium selenide (InAs/CdSe) core/shell nanocrystals emissive from 1.2 to 1.6 μm. We show that the average single InAs/CdSe nanocrystal fluorescence linewidth is, remarkably, as narrow as 52 meV, similar to what has been observed in some of the most narrowband nanostructured emitters in the visible region. Additionally, the single nanocrystal fluorescence linewidth increases with increasing shell thickness, suggesting exciton−phonon coupling as the dominant emission line-broadening mechanism in this system. The development of the SWIR s-PCFS technique has enabled measurements of spectral linewidths of colloidal SWIR-emissive NCs in solution and provides a platform to study the single NC spectral characteristics of SWIR emitters.

Highly Efficient, Bright, and Stable Colloidal Quantum Dot Short‐Wave Infrared Light‐Emitting Diodes

“…Light emission in the short‐wave infrared is of paramount importance for a large spectrum of applications including environmental sensing, surveillance, night and automotive vision, food and product quality control, on‐chip spectroscopy, biomedical imaging, and 3D imaging. [ 1–4 ] There is therefore an emerging need for low‐cost, CMOS compatible SWIR LED solutions with performance competitive to that of currently existing technologies based on rigid, non‐CMOS, and costly III–V semiconductors. Colloidal quantum dots (CQDs), in particular those based on lead‐chalcogenides, stand out as the most promising candidates currently to fulfill the required specifications.…”

“…Light emission in the short wave infrared is of paramount importance for a large spectrum of applications including environmental sensing, surveillance, night and automotive vision, food and product quality control, on-chip spectroscopy, biomedical imaging and 3D imaging [1][2][3][4].…”

Infrared Quantum Dots: Progress, Challenges, and Opportunities

“…The emission wavelengths of InAs QDs, for example, can readily cover most of the SWIR region. 17 The SWIR spectral region is particularly attractive as modern optical telecommunication operates almost exclusively in the C-band (1530−1565 nm) of the SWIR due to low Rayleigh scattering of optical fibers and the need for high-power transmission.…”

Release of Warfarin from Human Serum Albumin by Water‐soluble CdSe Nanotetrapods

“…Nanocrystals have attracted a lot of attention over the last few decades for their promise in a plethora of fields. [1][2][3][4][5] In recent times, the focus has shifted to a large extent on various exotic semiconductor nanocrystals. [6][7][8] CdSe nanotetrapods are Type-II core-shell nanostructures belonging to this family of nanocrystals due to the presence of zinc blende core.…”