Perovskite-based low-cost and high-efficiency hybrid
halide solar cells
Jiandong Fan, Baohua Jia, and Min Gu*
Centre for Micro-Photonics, Faculty of Science, Engineering and Technology, Swinburne University of Technology,
Hawthorn, Victoria 3122, Australia
*Corresponding author: mgu@swin.edu.au
Received May 12, 2014; revised July 9, 2014; accepted July 10, 2014;
posted July 16, 2014 (Doc. ID 211989); published August 11, 2014
A cost-effective and high-throughput material named perovskite has proven to be capable of converting 15.9%
of the solar energy to electricity, compared to an efficiency of 3.8% that was obtained only four years ago. It has
already outperformed most of the thin-film solar cell technologies that researchers have been studying for decades.
Currently, the architecture of perovskite solar cells has been simplified from the traditional dye-sensitized
solar cells to planar-heterojunction solar cells. Recently, the performance of perovskite in solar cells has attracted
intensive attention and studies. Foreseeably, many transformative steps will be put forward over the coming
few years. In this review, we summarize the recent exciting development in perovskite solar cells, and discuss
the fundamental mechanisms of perovskite materials in solar cells and their structural evolution. In addition,
future directions and prospects are proposed toward high-efficiency perovskite solar cells for practical
applications. © 2014 Chinese Laser Press
OCIS codes: (040.5350) Photovoltaic; (250.0250) Optoelectronics; (310.0310) Thin films.
http://dx.doi.org/10.1364/PRJ.2.000111
1. INTRODUCTION
Global energy consumption has been continually increasing
with population growth and fast-paced industrial development
in recent decades, which demands renewable energy sources
in view of long-term sustainable development. Generating
cost-effective and environmentally benign renewable energy
remains a major challenge for both technological and scien-
tific development [
1,2]. Solar cells based on the photovoltaic
effect with the advantages of decentralization and sustainabil-
ity have attracted great attention in the past 50 years.
Currently, the photovoltaics market is dominated by crystal-
line silicon-based solar cells with a share of 89% [
3]; however,
they suffer from low cost effectiveness, and they also have the
longest energy payback time of commercial photovoltaic
technologies [
4]. An emerging class of thin-film devices based
on amorphous silicon, CuIn; GaSe
2−x
S
x
, or CdTe, is begin-
ning to penetrate the market, which makes its headway in
terms of processing costs per unit area [
5–7]. However, the
manufacture of inorganic thin-film solar cells requires high
vacuum and high temperature-based techniques [
8]. In
addition, thin films containing low abundance and toxic
elements limit their large-scale production and widespread
application [
9].
Since their breakthrough in 1991 [
10], dye-sensitized solar
cells (DSSCs) have attracted considerable attention because
of their potential application in low-cost solar energy conver-
sion [
11–22]. As a consequence of the significant efforts in
DSSC-related research, a high efficiency exceeding 12% was
obtained by using a 10 μm mesoporous TiO
2
film sensitized
with organic dye and cobalt redox electrolyte [
23]. Meanwhile,
solid-state DSSCs have also been investigated, where the
liquid electrolyte was replaced by solid hole-transporting
materials [e.g., 2,2′,7,7′-tetrakis-(N,N-di-p-methoxyphenyl-
amine)-9,9’spirobifluorene (spiro-MeOTAD), poly(3-hexylth-
iophene) (P3HT), polyaniline, and polypyrrole] in order to
both simplify solar cell production and increase the open-
circuit voltage and stability of solar cells [
24–28]. However,
solid-state DSSCs suffer from faster electron recombination
dynamics between electrons in the TiO
2
and holes in the solid
hole transporter [
29], which results in the low efficiency of
solid-state DSSCs.
Recently, the perovskite sensitizer ABX
3
(A CH
3
NH
3
,
B Pb, Sn, and X Cl, Br, I) has attracted great attention
due to its superb light-harvesting characteristics [
30–60].
Moreover, perovskite is composed of inexpensive and earth
abundant materials. It is processable at low temperature
preferably via the printing techniques. In addition, it generates
charges freely in the bulk material after light absorption,
which enables low energy-loss charge generation and
collection [
61–63].
Within a short period from August 2012 to December 2013,
the power conversion efficiency (PCE) of perovskite-based
solar cells was significantly improved from 7.2% to 15.9%;
the high photo conversion efficiencies of these systems are
associated with the comparable optical absorption length
and charge-carrier diffusion lengths, transcending the tradi-
tional constraints of solution-processed semiconductors
[
30–60,64], and outperforming most other third-generation
thin-film solar cell technologies that have been studied for
decades (Fig.
1). This perovskite technology is now compat-
ible with the first- and second-generation technologies, and is
hence likely to be adopted by the conventional photovoltaics
community and industry. Therefore, it may find its way rapidly
into utility-scale power generation if some challenging issues,
for example, stability concerns of perovskite photovoltaics,
are to be solved effectively [
65].
Fan et al. Vol. 2, No. 5 / October 2014 / Photon. Res. 111
2327-9125/14/050111-10 © 2014 Chinese Laser Press