Near-Infrared Light-Emitting Diodes Based on RoHS-Compliant InAs/ZnSe Colloidal Quantum Dots

Abstract

We demonstrate efficient, stable, and fully RoHS-compliant nearinfrared (NIR) light-emitting diodes (LEDs) based on InAs/ZnSe quantum dots (QDs) synthesized by employing a commercially available amino-As precursor. They have a record external quantum efficiency of 5.5% at 947 nm and an operational lifetime of ∼32 h before reaching 50% of their initial luminance. Our findings offer a new solution for developing RoHS-compliant light-emitting technologies based on Pb-free colloidal QDs.

Indium arsenide quantum dots: an alternative to lead-based infrared emitting nanomaterials

“…InAs QDs have only marginally being tested in common optoelectronic devices such as LEDs 95,144,187,188 and photovoltaic cells. 27 Yet, to date, there have been no reports on amplified spontaneous emission or lasing from InAs QDs.…”

“…So, comprehensive XPS, FTIR, and NMR studies are needed since surface chemistry engineering is crucial to create ''strain-free'' core/shell systems (to increase their PLQY) and facilitate the development of InAs based NIR LEDs. 100,188 Future progress on novel precursors and synthetic methodologies should not only pursue the goal of making more luminescent InAs QDs, but also reduce non-radiative processes such as Auger recombination, specifically for QD-based optical gain media in the NIR range. In addition, the photo-as well as chemical-stability of InAs must be investigated in detail.…”

“… 187 It should be noted here that such performance was achieved using QDs with a relatively complex architecture, which requires an elaborate synthesis protocol based on both TMS-As and TMS-P. On the contrary, De Franco et al recently demonstrated a stable NIR LED based on much simpler InAs/ZnSe QDs synthesized via amino-As and reported EQE of 5.5% at 947 nm. 188 These works highlight the potential of InAs QDs for NIR LEDs; yet, they point out as well the necessity to develop efficient InAs QDs emitting in NIR-II region and device engineering for increasing the EQE of NIR LEDs.…”

Unraveling Luminescent Energy Transfer Pathways: Futuristic Approach of Miniature Shortwave Infrared Light-Emitting Diode Design

“…A shortwave infrared light (SWIR, 900–1700 nm) source in a compact size and operable with battery power is a critical need for delivering exciting answers to a wide range of spectroscopy, night surveillance, anticounterfeiting, solar cells, and bioimaging applications. − The phosphor-converted light-emitting diode (pc-LED) based on energy downshifting converter technology has been pursued as a promising energy device for infrared light and also an alternative to the well-known conventional SWIR light devices. , For example, pc-white LEDs have already revolutionized lighting and backlighting technologies by saving energy and trimming the device size, , and pc-LED devices based on Cr 3+ - and Eu 2+ -activated inorganic phosphors can emit near-infrared light around 600–1100 nm. − Obtaining emissions beyond 1100 nm using Cr 3+ , Bi 3+ , or Eu 2+ is difficult, while La 3 Ga 5 GeO 14 :Cr 3+ is the only reported super broadband (650–1200 nm) near-infrared phosphor, and its practical applications are limited. ,,, Thus, the development of SWIR-emitting luminous inorganic phosphors is a vital and urgent task.…”

Wurtzite InAs Nanocrystals with Short-Wavelength Infrared Emission Synthesized through the Cation Exchange of Cu3As Nanocrystals

“…Colloidal semiconductor nanocrystals (NCs) display exceptional optical properties, including size-dependent emission wavelength, wide spectral tunability, and good solution processability, leading to their successful implementation in a variety of optoelectronic device applications, including light-emitting diodes (LEDs) for solid-state displays, lighting, and photodetectors. − Compared with the most-studied group II–VI NCs, the group III–V NCs possess more covalent bonding lattices and hence lower permittivity and weaker screening. This is particularly attractive for photoelectric conversion processes, where efficient charge separation and extraction are mandatory. − Moreover, the heavy-metal-free nature of the group III–V NCs makes them promising candidates for next-generation, environmentally friendly optoelectronic devices. − Indeed, the toxic-element-containing feature of Cd- and Pb-based NCs severely restricts their applications in consumer electronics as required by regulations, which is one of the major obstacles toward commercialization. − …”