A Novel Approach for the Fabrication of All-Inorganic Nanocrystal Solids: Semiconductor Matrix Encapsulated Nanocrystal Arrays

A Novel Approach for the Fabrication of All-Inorganic Nanocrystal Solids: Semiconductor Matrix Encapsulated Nanocrystal Arrays

Bibliographic Details
Main Author: Moroz, Pavel
Language:English
Published: Bowling Green State University / OhioLINK 2015
Subjects:
Nanoscience
Semiconductor nanocrystals
thin films
charge transfer
IR emission
lead sulfide
Online Access:http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1435324105
id ndltd-OhioLink-oai-etd.ohiolink.edu-bgsu1435324105
record_format oai_dc
collection NDLTD
language English
sources NDLTD
topic Nanoscience
Semiconductor nanocrystals
thin films
charge transfer
IR emission
lead sulfide
spellingShingle Nanoscience
Semiconductor nanocrystals
thin films
charge transfer
IR emission
lead sulfide
Moroz, Pavel
A Novel Approach for the Fabrication of All-Inorganic Nanocrystal Solids: Semiconductor Matrix Encapsulated Nanocrystal Arrays
author Moroz, Pavel
author_facet Moroz, Pavel
author_sort Moroz, Pavel
title A Novel Approach for the Fabrication of All-Inorganic Nanocrystal Solids: Semiconductor Matrix Encapsulated Nanocrystal Arrays
title_short A Novel Approach for the Fabrication of All-Inorganic Nanocrystal Solids: Semiconductor Matrix Encapsulated Nanocrystal Arrays
title_full A Novel Approach for the Fabrication of All-Inorganic Nanocrystal Solids: Semiconductor Matrix Encapsulated Nanocrystal Arrays
title_fullStr A Novel Approach for the Fabrication of All-Inorganic Nanocrystal Solids: Semiconductor Matrix Encapsulated Nanocrystal Arrays
title_full_unstemmed A Novel Approach for the Fabrication of All-Inorganic Nanocrystal Solids: Semiconductor Matrix Encapsulated Nanocrystal Arrays
title_sort novel approach for the fabrication of all-inorganic nanocrystal solids: semiconductor matrix encapsulated nanocrystal arrays
publisher Bowling Green State University / OhioLINK
publishDate 2015
url http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1435324105
work_keys_str_mv AT morozpavel anovelapproachforthefabricationofallinorganicnanocrystalsolidssemiconductormatrixencapsulatednanocrystalarrays
AT morozpavel novelapproachforthefabricationofallinorganicnanocrystalsolidssemiconductormatrixencapsulatednanocrystalarrays
_version_ 1719438296234328064
spelling ndltd-OhioLink-oai-etd.ohiolink.edu-bgsu14353241052021-08-03T06:31:40Z A Novel Approach for the Fabrication of All-Inorganic Nanocrystal Solids: Semiconductor Matrix Encapsulated Nanocrystal Arrays Moroz, Pavel Nanoscience Semiconductor nanocrystals thin films charge transfer IR emission lead sulfide Growing fossil fuels consumption compels researchers to find new alternative pathways to produce energy. Along with new materials for the conversion of different types of energy into electricity innovative methods for efficient processing of energy sources are also introduced. The main criteria for the success of such materials and methods are the low cost and compelling performance. Among different types of materials semiconductor nanocrystals are considered as promising candidates for the role of the efficient and cheap absorbers for solar energy applications. In addition to the anticipated cost reduction, the integration of nanocrystals (NC) into device architectures is inspired by the possibility of tuning the energy of electrical charges in NCs via nanoparticle size. However, the stability of nanocrystals in photovoltaic devices is limited by the stability of organic ligands which passivate the surface of semiconductors to preserve quantum confinement.The present work introduces a new strategy for low-temperature processing of colloidal nanocrystals into all-inorganic films: semiconductor matrix encapsulated nanocrystal arrays (SMENA). This methodology goes beyond the traditional ligand-interlinking scheme and relies on the encapsulation of morphologically-defined nanocrystal arrays into a matrix of a wide-band gap semiconductor, which preserves optoelectronic properties of individual nanoparticles. Fabricated solids exhibit excellent thermal stability, which is attributed to the heteroepitaxial structure of nanocrystal-matrix interfaces. The main characteristics and properties of these solids were investigated and compared with ones of traditionally fabricated nanocrystal films using standard spectroscopic, optoelectronic and electronic techniques. As a proof of concept, wesuccessfully fabricated an all-inorganic depleted-heterojunction solar cell prototype which shows a promising 4.0% power conversion efficiency.We also characterized electron transport phenomena in different types of nanocrystal films using all-optical approach. By measuring excited carrier lifetimes in either ligand-linked or matrix-encapsulated PbS nanocrystal films containing a tunable fraction of insulating ZnS domains, we uniquely distinguish the dynamics of charge scattering on defects from other processes of exciton dissociation. The measured times are subsequently used to estimate the diffusion length and the carrier mobility for each film type within hopping transport regime. It is demonstrated that nanocrystal films encapsulated into semiconductor matrices exhibit a lower probability of charge scattering than nanocrystal solids cross-linked with either 3-mercaptopropionic acid or 1,2-ethanedithiol molecular linkers. The suppression of carrier scattering in matrix-encapsulated nanocrystal films is attributed to a relatively low density of surface defects at nanocrystal/matrix interfaces.High stability and low density of defects made it possible to fabricate infrared-emitting nanocrystal solids. Presently, an important challenge facing the development of nanocrystal infrared emitters concerns the fact that both the emission quantum yield and the stability of colloidal nanoparticles become compromised when nanoparticle solutions are processed into solids. Here, we address this issue by developing an assembly technique that encapsulates infrared-emitting PbS NCs into crystalline CdS matrices, designed to preserve NC emission characteristics upon film processing. Here, the morphology of these matrices was designed to suppress the nonradiative carrier decay, whereby increasing the exciton lifetime up to 1 µs, and boosting the emission quantum yield to an unprecedented 3.7% for inorganically encapsulated PbS NC solids 2015-07-23 English text Bowling Green State University / OhioLINK http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1435324105 http://rave.ohiolink.edu/etdc/view?acc_num=bgsu1435324105 unrestricted This thesis or dissertation is protected by copyright: some rights reserved. It is licensed for use under a Creative Commons license. Specific terms and permissions are available from this document's record in the OhioLINK ETD Center.

Similar Items