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Title: Space charge limited conduction in ultrathin PbS quantum dot solid diodes

As a simple and direct characterization of carrier transport in nanocrystal quantum dot (NQD) solids, current-voltage characterization of ultrathin diodes is proposed. We found the space charge limited conduction (SCLC) behavior in ultrathin PbS NQD diodes with active layer thickness half of the full depletion width; and extracted hole concentrations in the order of 10{sup 15} cm{sup −3}, hole mobilities from 10{sup −4} to 10{sup −5} cm{sup 2}/Vs, trap energy depths varying from 140 meV to 200 meV, and volume trap density around 10{sup 17} cm{sup −3} for thin films with NQDs of diameters 3.3 and 3.6 nm, respectively. We further discuss the validity of applying SCLC to the NQD solids based diodes and the implications of the extracted parameters extensively. Proposed characterization method here is a direct measure of carrier transport in solar cell structures which could provide exact directions in NQD solids based solar cell fabrication and modeling.
Authors:
 [1] ;  [1] ;  [2] ; ;  [1] ;  [2] ;  [3]
  1. Nanomechanical Systems Research Division, Korea Institute of Machinery and Materials, Yuseong-gu, Daejeon 305-343 (Korea, Republic of)
  2. (Korea, Republic of)
  3. Department of Electrical, Electronic, and Control Engineering, Hankyong National University, Anseong-si, Gyeonggi-do 456-749 (Korea, Republic of)
Publication Date:
OSTI Identifier:
22278160
Resource Type:
Journal Article
Resource Relation:
Journal Name: Journal of Applied Physics; Journal Volume: 115; Journal Issue: 5; Other Information: (c) 2014 AIP Publishing LLC; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
77 NANOSCIENCE AND NANOTECHNOLOGY; 75 CONDENSED MATTER PHYSICS, SUPERCONDUCTIVITY AND SUPERFLUIDITY; COMPUTERIZED SIMULATION; CONCENTRATION RATIO; ELECTRIC CONDUCTIVITY; FABRICATION; HOLE MOBILITY; HOLES; LEAD SULFIDES; QUANTUM DOTS; SOLAR CELLS; SOLIDS; SPACE CHARGE; THIN FILMS; TRAPS