N AN O E X P R E S S Open Access
Optoelectronic Evaluation and Loss Analysis
of PEDOT:PSS/Si Hybrid Heterojunction
Solar Cells
Zhenhai Yang
1
, Zebo Fang
2
, Jiang Sheng
1
, Zhaoheng Ling
1
, Zhaolang Liu
1
, Juye Zhu
1
, Pingqi Gao
1*
and Jichun Ye
1
Abstract
The organic/silicon (Si) hybrid heterojunction solar cells (HHSCs) have attracted considerable attention due to their
potential advantages in high efficiency and low cost. However, as a newly arisen photovoltaic device, its current
efficiency is still much worse than commerciall y available Si solar cells. Therefore, a comprehensive and systematical
optoelectronic evaluation and loss analysis on this HHSC is therefore highly necessary to fully explore its efficiency
potential. Here, a thoroughly optoelectronic simulation is provided on a typical planar polymer poly (3,4-ethylenedioxy
thiophene):polystyrenesulfonate (PEDOT:PSS)/Si HHSC. The calculated spectra of reflection and external quantum
efficiency (EQE) match well with the experimental results in a full-wavelength range. The losses in current density,
which are contributed by both optical losses (i.e., reflection, electrode shield, and parasitic absorption) and electrical
recombination (i.e., the bulk and surface recombination), are predicted via carefully addressing the electromagnetic and
carrier-transport processes. In addition, the effects of Si doping concentrations and rear surface recombination velocities
on the device performance are fully investigated. The results drawn in this study are beneficial to the guidance of
designing high-performance PEDOT:PSS/Si HHSCs.
Keywords: Hybrid solar cells, Optoelectronic loss, PEDOT:PSS/Si
PACS: 85.60.-q, Optoelectronic device, 84.60.Jt, Photovoltaic conversion
Background
Although conventional p-n junction silicon solar cells
(SCs) dominate photovoltaic (PV) market , the relevant
applications ha ve been substantially restricted by relatively
high production cost, which can be partially attributed to
their complicated fabrication process [1]. Recently, organic/
silicon (Si) hybrid heterojunction solar cells (HHSCs) that
combine the advantages of the Si base with the organic
functional layer have attracted much attention [2, 3]. In
particular, a p-type polymer of poly(3,4-ethylenedioxy
thiophene):polystyrenesulfonate (PEDOT:PSS) with a
relatively high work function and a wide bandgap has been
widely used in HHSCs as a hole-conductive material
[4–7]. According to previous reports , power conversion
efficiencies (PCEs) of over 13% have been achieved for
PEDOT:PSS/Si HHSCs by a simple spin-coating method,
demonstrating their great potentials in future photovoltaic
application [8–16].
However, compared to the traditional SCs, the relatively
poor PCE for this kind of HHSC is still the main challenge
that prevent them from becoming a competitive PV tech-
nology. Chi et al. demonstrated that the conductivity and
wettability of the PEDOT:PSS film can be markedly im-
proved by incorporating different additives into the PED-
OT:PSS solution, and the performance of PEDOT:PSS/Si
HHSCs was greatly enhanced accordingly [17]. Yu et al.
reported a PCE of up to 13.7% for PEDOT:PSS/Si HHSCs
on nanostructured Si through engineering the interface by
adding a solution-processed cesium carbonate layer [18].
Liu et al demonstrated a PCE of 15.5% due to increased
conductivity through the addition of p-toluenesulfonic
acid into PEDOT:PSS as well as enhanced light-harvesting
* Correspondence: gaopingqi@nimte.ac.cn
1
Ningbo Institute of Material Technology and Engineering, Chinese Academy
of Sciences, Ningbo 315201, China
Full list of author information is available at the end of the article
© The Author(s). 2017 Open Access This article is distributed under the terms of the Creative Commons Attribution 4.0
International License (http://creativecommons.org/licenses/by/4.0/), which permits unrestricted use, distribution, and
reproduction in any medium, provided you give appropriate credit to the original author(s) and the source, provide a link to
the Creative Commons license, and indicate if changes were made.
Yang et al. Nanoscale Research Letters (2017) 12:26
DOI 10.1186/s11671-016-1790-1