Excitonic effects in emerging photovoltaic materials

A case study in Cu2O

Stefan T. Omelchenko, Yulia Tolstova, Harry A. Atwater, Nathan S Lewis

Research output: Contribution to journalArticle

6 Citations (Scopus)

Abstract

Excitonic effects account for a fundamental photoconversion and charge transport mechanism in Cu2O; hence, the universally adopted "free carrier" model substantially underestimates the photovoltaic efficiency for such devices. The quasi-equilibrium branching ratio between excitons and free carriers in Cu2O indicates that up to 28% of photogenerated carriers during photovoltaic operation are excitons. These large exciton densities were directly observed in photoluminescence and spectral response measurements. The results of a device physics simulation using a model that includes excitonic effects agree well with experimentally measured current-voltage characteristics of Cu2O-based photovoltaics. In the case of Cu2O, the free carrier model underestimates the efficiency of a Cu2O solar cell by as much as 1.9 absolute percent at room temperature.

Original languageEnglish
Pages (from-to)431-437
Number of pages7
JournalACS Energy Letters
Volume2
Issue number2
DOIs
Publication statusPublished - Feb 10 2017

Fingerprint

Excitons
Current voltage characteristics
Charge transfer
Solar cells
Photoluminescence
Physics
LDS 751
Temperature

ASJC Scopus subject areas

  • Chemistry (miscellaneous)
  • Energy Engineering and Power Technology
  • Fuel Technology
  • Renewable Energy, Sustainability and the Environment
  • Materials Chemistry

Cite this

Excitonic effects in emerging photovoltaic materials : A case study in Cu2O. / Omelchenko, Stefan T.; Tolstova, Yulia; Atwater, Harry A.; Lewis, Nathan S.

In: ACS Energy Letters, Vol. 2, No. 2, 10.02.2017, p. 431-437.

Research output: Contribution to journalArticle

Omelchenko, Stefan T. ; Tolstova, Yulia ; Atwater, Harry A. ; Lewis, Nathan S. / Excitonic effects in emerging photovoltaic materials : A case study in Cu2O. In: ACS Energy Letters. 2017 ; Vol. 2, No. 2. pp. 431-437.
@article{3f9bec9fffcc491ab7f6a9e2279607b8,
title = "Excitonic effects in emerging photovoltaic materials: A case study in Cu2O",
abstract = "Excitonic effects account for a fundamental photoconversion and charge transport mechanism in Cu2O; hence, the universally adopted {"}free carrier{"} model substantially underestimates the photovoltaic efficiency for such devices. The quasi-equilibrium branching ratio between excitons and free carriers in Cu2O indicates that up to 28{\%} of photogenerated carriers during photovoltaic operation are excitons. These large exciton densities were directly observed in photoluminescence and spectral response measurements. The results of a device physics simulation using a model that includes excitonic effects agree well with experimentally measured current-voltage characteristics of Cu2O-based photovoltaics. In the case of Cu2O, the free carrier model underestimates the efficiency of a Cu2O solar cell by as much as 1.9 absolute percent at room temperature.",
author = "Omelchenko, {Stefan T.} and Yulia Tolstova and Atwater, {Harry A.} and Lewis, {Nathan S}",
year = "2017",
month = "2",
day = "10",
doi = "10.1021/acsenergylett.6b00704",
language = "English",
volume = "2",
pages = "431--437",
journal = "ACS Energy Letters",
issn = "2380-8195",
publisher = "American Chemical Society",
number = "2",

}

TY - JOUR

T1 - Excitonic effects in emerging photovoltaic materials

T2 - A case study in Cu2O

AU - Omelchenko, Stefan T.

AU - Tolstova, Yulia

AU - Atwater, Harry A.

AU - Lewis, Nathan S

PY - 2017/2/10

Y1 - 2017/2/10

N2 - Excitonic effects account for a fundamental photoconversion and charge transport mechanism in Cu2O; hence, the universally adopted "free carrier" model substantially underestimates the photovoltaic efficiency for such devices. The quasi-equilibrium branching ratio between excitons and free carriers in Cu2O indicates that up to 28% of photogenerated carriers during photovoltaic operation are excitons. These large exciton densities were directly observed in photoluminescence and spectral response measurements. The results of a device physics simulation using a model that includes excitonic effects agree well with experimentally measured current-voltage characteristics of Cu2O-based photovoltaics. In the case of Cu2O, the free carrier model underestimates the efficiency of a Cu2O solar cell by as much as 1.9 absolute percent at room temperature.

AB - Excitonic effects account for a fundamental photoconversion and charge transport mechanism in Cu2O; hence, the universally adopted "free carrier" model substantially underestimates the photovoltaic efficiency for such devices. The quasi-equilibrium branching ratio between excitons and free carriers in Cu2O indicates that up to 28% of photogenerated carriers during photovoltaic operation are excitons. These large exciton densities were directly observed in photoluminescence and spectral response measurements. The results of a device physics simulation using a model that includes excitonic effects agree well with experimentally measured current-voltage characteristics of Cu2O-based photovoltaics. In the case of Cu2O, the free carrier model underestimates the efficiency of a Cu2O solar cell by as much as 1.9 absolute percent at room temperature.

UR - http://www.scopus.com/inward/record.url?scp=85032702197&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=85032702197&partnerID=8YFLogxK

U2 - 10.1021/acsenergylett.6b00704

DO - 10.1021/acsenergylett.6b00704

M3 - Article

VL - 2

SP - 431

EP - 437

JO - ACS Energy Letters

JF - ACS Energy Letters

SN - 2380-8195

IS - 2

ER -