Strain-Induced Type II Band Alignment Control in CdSe Nanoplatelet/ZnS-Sensitized Solar Cells

Songping Luo, Miri Kazes, Hong Lin, Dan Oron

Research output: Contribution to journalArticle

5 Citations (Scopus)

Abstract

Colloidal CdSe nanoplatelets (NPLs) deposited on TiO2 and overcoated by ZnS were explored as light absorbers in semiconductor-sensitized solar cells (SSSCs). Significant red shifts of both absorption and steady-state photoluminescence (PL) along with rapid PL quenching suggest a type II band alignment at the interface of the CdSe NPL and the ZnS barrier layer grown on the NPL layer, as confirmed by energy band measurements. The considerable red shift leads to enhanced spectral absorption coverage. Cell characterization shows an increased open-circuit voltage of 664 mV using a polysulfide electrolyte, which can be attributed to a photoinduced dipole effect created by the spatial charge separation across the nanoplatelet sensitizers. The observed short-circuit current density of 11.14 mA cm-2 approaches the maximal theoretical current density for this choice of absorber, yielding an internal quantum efficiency of close to 100%, a clear signature of excellent charge transport and collection yields. With their steep absorption onset and negligible inhomogeneous broadening, NPL-based SSSCs are intriguing candidates for future high-voltage sensitized cells.

Original languageEnglish
Pages (from-to)11136-11143
Number of pages8
JournalJournal of Physical Chemistry C
Volume121
Issue number21
DOIs
Publication statusPublished - Jun 1 2017

Fingerprint

red shift
absorbers
Solar cells
Photoluminescence
Current density
solar cells
alignment
Semiconductor materials
current density
polysulfides
photoluminescence
Polysulfides
Open circuit voltage
polarization (charge separation)
barrier layers
short circuit currents
open circuit voltage
cells
Quantum efficiency
Short circuit currents

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Energy(all)
  • Surfaces, Coatings and Films
  • Physical and Theoretical Chemistry

Cite this

Strain-Induced Type II Band Alignment Control in CdSe Nanoplatelet/ZnS-Sensitized Solar Cells. / Luo, Songping; Kazes, Miri; Lin, Hong; Oron, Dan.

In: Journal of Physical Chemistry C, Vol. 121, No. 21, 01.06.2017, p. 11136-11143.

Research output: Contribution to journalArticle

Luo, Songping ; Kazes, Miri ; Lin, Hong ; Oron, Dan. / Strain-Induced Type II Band Alignment Control in CdSe Nanoplatelet/ZnS-Sensitized Solar Cells. In: Journal of Physical Chemistry C. 2017 ; Vol. 121, No. 21. pp. 11136-11143.
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