Electronic coupling in superlattices of HgTe quantum dots. Organization, transport, and spectroscopy
Abstract
HgTe quantum dot superlattices are explored to see if extended structural order improves infrared photodetection. The research is motivated by recent works reporting extraordinary electronic transport properties from ordered and coupled nanocrystal arrays, such as #bulk-like# mobility (PbSe, PbS) and very long hot electron transport (HgTe). The work will start with the synthesis of the monodispersed HgTe quantum dots with absorption in the mid- and long-wave infrared, and the fabrication and structural characterization ofthe superlattices. The electronic properties of the superlattices will then be compared to those of disordered films made from the same quantum dots. The properties of interest include doping, mobility, photocarrier lifetime, 1/f noise, and thermoelectric response. Devices will be operated as photoconductors and as photodiodes. The work will then explore surface passivation to improve carrierlifetime and enhance photoresponse. The superlattice fabrication and processing is directly informed by feedback from the electrical and optical characterizations, such as the doping and mobility for example. In the best-case scenario, the recently reported extraordinary transport properties emerging from electronically coupled CQD superlattices are confirmed, including #bulk-like# mobility, much reduced carrier scattering, micrometer-long coherence length, and extraordinarily slow hot electron relaxation. These properties then lead to enhanced responsivity and reduced 1/f noise, and one can envision self-cooling of diode junctions for devices operating out of equilibrium under reverse bias.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Jan 13, 2025
- Source ID
- N000142512117
Entities
People
- Philippe Guyot-Sionnest
Organizations
- Office of Naval Research
- United States Navy
- University of Chicago