Query: photovoltaics

Candidate papers:

abstract: The photovoltaics of organic inorganic lead halide perovskite materials have shown rapid improvements in solar cell performance, surpassing the top efficiency of semiconductor compounds such as CdTe and CIGS (copper indium gallium selenide) used in solar cells in just about a decade. Perovskite preparation via simple and inexpensive solution processes demonstrates the immense potential of this thin film solar cell technology to become a low cost alternative to the presently commercially available photovoltaic technologies. Significant developments in almost all aspects of perovskite solar cells and discoveries of some fascinating properties of such hybrid perovskites have been made recently. This Review describes the fundamentals, recent research progress, present status, and our views on future prospects of perovskite based photovoltaics, with discussions focused on strategies to improve both intrinsic and extrinsic (environmental) stabilities of high efficiency devices. Strategies and challenges regarding compositional engineering of the hybrid perovskite structure are discussed, including potentials for developing all inorganic and lead free perovskite materials. Looking at the latest cutting edge research, the prospects for perovskite based photovoltaic and optoelectronic devices, including non photovoltaic applications such as X ray detectors and image sensing devices in industrialization, are described. In addition to the aforementioned major topics, we also review, as a background, our encounter with perovskite materials for the first solar cell application, which should inspire young researchers in chemistry and physics to identify and work on challenging interdisciplinary research problems through exchanges between academia and industry.
author_names: Ajay Kumar Jena

Ashish Kulkarni

Tsutomu Miyasaka
title: Halide Perovskite Photovoltaics: Background, Status, and Future Prospects.
venue: Chemical reviews
year: 2019

abstract: Despite significant development recently, improving the power conversion efficiency of organic photovoltaics (OPVs) is still an ongoing challenge to overcome. One of the prerequisites to achieving this goal is to enable efficient charge separation and small voltage losses at the same time. In this work, a facile synthetic strategy is reported, where optoelectronic properties are delicately tuned by the introduction of electron deficient core based fused structure into non fullerene acceptors. Both devices exhibited a low voltage loss of 0.57 V and high short circuit current density of 22.0 mA cm 2, resulting in high power conversion efficiencies of over 13.4% These unconventional electron deficient core based non fullerene acceptors with near infrared absorption lead to low non radiative recombination losses in the resulting organic photovoltaics, contributing to a certified high power conversion efficiency of 12.6%.Improving the power conversion efficiency is the main target of the organic solar cell research. Here Yuan et al. develop unconventional electron deficient core based non fullerene acceptors to achieve both low voltage loss and high current density, leading to a certified high efficiency of 12.6%
author_names: Jun Yuan

Tianyi Huang

Pei Cheng

Yingping Zou

Huotian Zhang

Jonathan Lee Yang

Sheng-Yung Chang

Zhenzhen Zhang

Wenchao Huang

Rui Wang

Dong Meng

Feng Gao

Yang Yang
title: Enabling low voltage losses and high photocurrent in fullerene free organic photovoltaics
venue: Nature Communications
year: 2019

abstract: Over the past three years, a particularly exciting and active area of research within the field of organic photovoltaics has been the use of non fullerene acceptors (NFAs) Compared with fullerene acceptors, NFAs possess significant advantages including tunability of bandgaps, energy levels, planarity and crystallinity. To date, NFA solar cells have not only achieved impressive power conversion efficiencies of ~13 14% but have also shown excellent stability compared with traditional fullerene acceptor solar cells. This Review highlights recent progress on single junction and tandem NFA solar cells and research directions to achieve even higher efficiencies of 15 20% using NFA based organic photovoltaics are also proposed.This Review describes how non fullerene electron acceptor materials are bringing improvements in the power conversion efficiency and stability of organic solar cells.
author_names: Pei Cheng

Gang Li

Xiaowei Zhan

Yang Yang
title: Next generation organic photovoltaics based on non fullerene acceptors
year: 2018

abstract: 2D materials have attracted considerable attention due to their exciting optical and electronic properties, and demonstrate immense potential for next generation solar cells and other optoelectronic devices. With the scaling trends in photovoltaics moving toward thinner active materials, the atomically thin bodies and high flexibility of 2D materials make them the obvious choice for integration with future generation photovoltaic technology. Not only can graphene, with its high transparency and conductivity, be used as the electrodes in solar cells, but also its ambipolar electrical transport enables it to serve as both the anode and the cathode. 2D materials beyond graphene, such as transition metal dichalcogenides, are direct bandgap semiconductors at the monolayer level, and they can be used as the active layer in ultrathin flexible solar cells. However, since no 2D material has been featured in the roadmap of standard photovoltaic technologies, a proper synergy is still lacking between the recently growing 2D community and the conventional solar community. A comprehensive review on the current state of the art of 2D materials based solar photovoltaics is presented here so that the recent advances of 2D materials for solar cells can be employed for formulating the future roadmap of various photovoltaic technologies.
author_names: Sonali Das

Deepak Pandey

Jayan Thomas

Tania Roy
title: The Role of Graphene and Other 2D Materials in Solar Photovoltaics.
venue: Advanced materials
year: 2019

abstract: The power of a pair of perovskites In the past several years, perovskite solar cells have emerged as a low cost experimental alternative to more traditional silicon devices. Luo et al. now show that a pair of perovskite cells connected in series can power the electrochemical breakdown of water into hydrogen and oxygen efficiently (see the Perspective by Hamann) Hydrogen generation from water is being actively studied as a supplement in solar power generation to smooth out the fluctuations due to variations in sunlight. Science, this issue p. 1593; see also p. 1566 A pair of perovskite solar cells can power efficient hydrogen generation from water. [Also see Perspective by Hamann] Although sunlight driven water splitting is a promising route to sustainable hydrogen fuel production, widespread implementation is hampered by the expense of the necessary photovoltaic and photoelectrochemical apparatus. Here, we describe a highly efficient and low cost water splitting cell combining a state of the art solution processed perovskite tandem solar cell and a bifunctional Earth abundant catalyst. The catalyst electrode, a NiFe layered double hydroxide, exhibits high activity toward both the oxygen and hydrogen evolution reactions in alkaline electrolyte. The combination of the two yields a water splitting photocurrent density of around 10 milliamperes per square centimeter, corresponding to a solar to hydrogen efficiency of 12.3% Currently, the perovskite instability limits the cell lifetime.
author_names: Jingshan Luo

Jeong Hyeok Im

Matthew T Mayer

Marcel Schreier

Mohammad Khaja Nazeeruddin

Nam-Gyu Park

S David Tilley

Hong Jin Fan

Michael Gratzel
title: Water photolysis at 12.3% efficiency via perovskite photovoltaics and Earth abundant catalysts
venue: Science
year: 2014

abstract: Impedance spectroscopy has been widely applied over the last decades to study electrochemical systems and solid state devices. However, performing impedance spectroscopy on emerging photovoltaics presents new challenges related to the unusual material properties and complex device architectures. This review provides an introduction to impedance spectroscopy for researchers in photovoltaics and closely related fields. The review begins with a list of practical guidelines for performing measurements and analyzing data. After this, the mathematical basics are reviewed, and an introduction to circuit elements is given. This is followed by tips for collecting reliable data and reducing artifacts in the frequency spectra. The review then surveys common approaches in the field for analyzing data, including performing equivalent circuit modeling, analysis of capacitance frequency spectra, and carrier mobility measurements. The underlying assumptions of each analysis approach, as well as the advantages, limitation.
author_names: Elizabeth von Hauff
title: Impedance Spectroscopy for Emerging Photovoltaics
venue: The Journal of Physical Chemistry C
year: 2019

author_names: Karin Schneider
title: Recent Facts about Photovoltaics in Germany
year: 2017

abstract: Hybrid perovskites are currently one of the most active fields of research owing to their enormous potential for photovoltaics. The performance of 3D hybrid organic inorganic perovskite solar cells has increased at an incredible rate, reaching power conversion efficiencies comparable to those of many established technologies. However, the commercial application of 3D hybrid perovskites is inhibited by their poor stability. Relative to 3D hybrid perovskites, low dimensional that is, 2D hybrid perovskites have demonstrated higher moisture stability, offering new approaches to stabilizing perovskite based photovoltaic devices. Furthermore, 2D hybrid perovskites have versatile structures, enabling the fine tuning of their optoelectronic properties through compositional engineering. In this Review, we discuss the state of the art in 2D perovskites, providing an overview of structural and materials engineering aspects and optical and photophysical properties. Moreover, we discuss recent developments along with the main limitations of 3D perovskites and assess the advantages of 2D perovskites over their 3D parent structures in terms of stability. Finally, we review recent achievements in combining 3D and 2D perovskites as an approach to simultaneously boost device efficiency and stability, paving the way for mixed dimensional perovskite solar cells for commercial applications.Combining low dimensional and 3D perovskites is a promising approach to achieve stable and efficient solar cells. In this Review, we discuss the structural, optical and photophysical properties of low dimensional perovskites, compare the stability and efficiency of 2D and 3D perovskite devices, and consider 2D/3D composites as a strategy to increase the stability of perovskite solar cells.
author_names: Giulia Grancini

Mohammad Khaja Nazeeruddin
title: Dimensional tailoring of hybrid perovskites for photovoltaics
venue: Nature Reviews Materials
year: 2018

abstract: The performance of organic photovoltaics is largely dependent on the balance of short circuit current density (JSC) and open circuit voltage (VOC) For instance, the reduction of the active materials' optical bandgap, which increases the JSC, would inevitably lead to a concomitant reduction in VOC. Here, we demonstrate that careful tuning of the chemical structure of photoactive materials can enhance both JSC and VOC simultaneously. Non fullerene organic photovoltaics based on a well matched materials combination exhibit a certified high power conversion efficiency of 12.25% on a device area of 1 cm2. By combining Fourier transform photocurrent spectroscopy and electroluminescence, we show the existence of a low but non negligible charge transfer state as the possible origin of VOC loss. This study highlights that the reduction of the bandgap to improve the efficiency requires a careful materials design to minimize non radiative VOC losses.Materials design rules play a key role in enabling high performance in organic photovoltaics. Here the authors achieve 12.25% efficiency on 1 cm2 non fullerene solar cells by tuning the side chains' branching point and the fluorine substitutions in donor and acceptor materials.
author_names: Baobing Fan

Xiaoyang Du

Feng Liu

Wenkai Zhong

Lei Ying

Ruihao Xie

Xiaofeng Tang

Kang An

Jingming Xin

Ning Li

Wei Ma

Christoph J Brabec

Fei Huang

Yongli Cao
title: Fine tuning of the chemical structure of photoactive materials for highly efficient organic photovoltaics
year: 2018

abstract: The development of organic semiconductors for photovoltaic devices, over the last three decades, has led to unexpected performance for an alternative choice of materials to convert sunlight to electricity. New materials and developed concepts have improved the photovoltage in organic photovoltaic devices, where records are now found above 13% power conversion efficiency in sunlight. The author has stayed with the topic of organic materials for energy conversion and energy storage during these three decades, and makes use of the Hall of Fame now built by Advanced Materials, to present his view of the path travelled over this time, including motivations, personalities, and ambitions.
author_names: Olle Inganas
title: Organic Photovoltaics over Three Decades.
venue: Advanced materials
year: 2018