scholarly journals Ba-induced phase segregation and band gap reduction in mixed-halide inorganic perovskite solar cells

2019 ◽  
Vol 10 (1) ◽  
Author(s):  
Wanchun Xiang ◽  
Zaiwei Wang ◽  
Dominik J. Kubicki ◽  
Xueting Wang ◽  
Wolfgang Tress ◽  
...  
Keyword(s):  
Solar Cells ◽  
Band Gap ◽  
Perovskite Phase ◽  
Perovskite Solar Cells ◽  
Phase Segregation ◽  
Band Gap Energy ◽  
Open Circuit ◽  
High Power Conversion Efficiency ◽  
Inorganic Perovskite ◽  
High Efficient

Abstract All-inorganic metal halide perovskites are showing promising development towards efficient long-term stable materials and solar cells. Element doping, especially on the lead site, has been proved to be a useful strategy to obtain the desired film quality and material phase for high efficient and stable inorganic perovskite solar cells. Here we demonstrate a function by adding barium in CsPbI2Br. We find that barium is not incorporated into the perovskite lattice but induces phase segregation, resulting in a change in the iodide/bromide ratio compared with the precursor stoichiometry and consequently a reduction in the band gap energy of the perovskite phase. The device with 20 mol% barium shows a high power conversion efficiency of 14.0% and a great suppression of non-radiative recombination within the inorganic perovskite, yielding a high open-circuit voltage of 1.33 V and an external quantum efficiency of electroluminescence of 10−4.

Triple-halide wide–band gap perovskites with suppressed phase segregation for efficient tandems

Science ◽  
2020 ◽  
Vol 367 (6482) ◽  
pp. 1097-1104 ◽  
Author(s):  
Jixian Xu ◽  
Caleb C. Boyd ◽  
Zhengshan J. Yu ◽  
Axel F. Palmstrom ◽  
Daniel J. Witter ◽  
...  
Keyword(s):  
Solar Cells ◽  
Band Gap ◽  
Low Cost ◽  
Perovskite Solar Cells ◽  
Phase Segregation ◽  
Wide Band ◽  
Charge Carrier Mobility ◽  
Lattice Parameter ◽  
Open Circuit ◽  
Wide Band Gap

Wide–band gap metal halide perovskites are promising semiconductors to pair with silicon in tandem solar cells to pursue the goal of achieving power conversion efficiency (PCE) greater than 30% at low cost. However, wide–band gap perovskite solar cells have been fundamentally limited by photoinduced phase segregation and low open-circuit voltage. We report efficient 1.67–electron volt wide–band gap perovskite top cells using triple-halide alloys (chlorine, bromine, iodine) to tailor the band gap and stabilize the semiconductor under illumination. We show a factor of 2 increase in photocarrier lifetime and charge-carrier mobility that resulted from enhancing the solubility of chlorine by replacing some of the iodine with bromine to shrink the lattice parameter. We observed a suppression of light-induced phase segregation in films even at 100-sun illumination intensity and less than 4% degradation in semitransparent top cells after 1000 hours of maximum power point (MPP) operation at 60°C. By integrating these top cells with silicon bottom cells, we achieved a PCE of 27% in two-terminal monolithic tandems with an area of 1 square centimeter.

Lattice reconstruction of La-incorporated CsPbI2Br with suppressed phase transition for air-processed all-inorganic perovskite solar cells

2020 ◽  
Vol 8 (10) ◽  
pp. 3351-3358 ◽  
Author(s):  
Shoulong Chen ◽  
Tianju Zhang ◽  
Xiaolin Liu ◽  
Jinli Qiao ◽  
Lin Peng ◽  
...  
Keyword(s):  
Phase Transition ◽  
Solar Cells ◽  
Perovskite Phase ◽  
Perovskite Solar Cells ◽  
Inorganic Perovskite

A stable CsPbI2Br perovskite phase can be achieved when doped with an appropriate amount of La3+ ions.

High Efficient Hole Extraction and Stable All‐Bromide Inorganic Perovskite Solar Cells via Derivative‐Phase Gradient Bandgap Architecture

Solar RRL ◽  
2019 ◽  
Vol 3 (5) ◽  
pp. 1900030 ◽  
Author(s):  
Guoqing Tong ◽  
Taotao Chen ◽  
Huan Li ◽  
Wentao Song ◽  
Yajing Chang ◽  
...  
Keyword(s):  
Solar Cells ◽  
Perovskite Solar Cells ◽  
Phase Gradient ◽  
Inorganic Perovskite ◽  
High Efficient

Tailoring the Open-Circuit Voltage Deficit of Wide-Band-Gap Perovskite Solar Cells Using Alkyl Chain-Substituted Fullerene Derivatives

2018 ◽  
Vol 10 (26) ◽  
pp. 22074-22082 ◽  
Author(s):  
Dhruba B. Khadka ◽  
Yasuhiro Shirai ◽  
Masatoshi Yanagida ◽  
Takeshi Noda ◽  
Kenjiro Miyano
Keyword(s):  
Solar Cells ◽  
Band Gap ◽  
Open Circuit Voltage ◽  
Alkyl Chain ◽  
Perovskite Solar Cells ◽  
Wide Band ◽  
Open Circuit ◽  
Wide Band Gap ◽  
Fullerene Derivatives

scholarly journals Chemi-Structural Stabilization of Formamidinium Lead Iodide Perovskite by Using Embedded Quantum Dots for High-Performance Solar Cells

2019 ◽  
Author(s):  
Sofia Masi ◽  
Carlos Echeverría-Arrondo ◽  
Salim K.P. Muhammed ◽  
Thi Tuyen Ngo ◽  
Perla F. Méndez ◽  
...  
Keyword(s):  
Quantum Dots ◽  
Solar Cells ◽  
Band Gap ◽  
High Efficiency ◽  
Perovskite Phase ◽  
Perovskite Solar Cells ◽  
Relative Size ◽  
Lead Iodide ◽  
Structural Stabilization ◽  
Halide Perovskites

<b>The extraordinary low non-radiative recombination and band gap versatility of halide perovskites have led to considerable development in optoelectronic devices. However, this versatility is limited by the stability of the perovskite phase, related to the relative size of the different cations and anions. The most emblematic case is that of formamidinium lead iodine (FAPI) black phase, which has the lowest band gap among all 3D lead halide perovskites, but quickly transforms into the non-perovskite yellow phase at room temperature. Efforts to optimize perovskite solar cells have largely focused on the stabilization of FAPI based perovskite structures, often introducing alternative anions and cations. However, these approaches commonly result in a blue-shift of the band gap, which limits the maximum photo-conversion efficiency. Here, we report the use of PbS colloidal quantum dots (QDs) as stabilizing agent for the FAPI perovskite black phase. The surface chemistry of PbS plays a pivotal role, by developing strong bonds with the black phase but weak ones with the yellow phase. As a result, stable FAPI black phase can be formed at temperatures as low as 85°C in just 10 minutes, setting a record of concomitantly fast and low temperature formation for FAPI, with important consequences for industrialization. FAPI thin films obtained through this procedure preserve the original low band gap of 1.5 eV, reach a record open circuit potential (V<sub>oc</sub>) of 1.105 V -91% of the maximum theoretical V<sub>oc</sub>- and preserve high efficiency for more than 700 hours. These findings reveal the potential of strategies exploiting the chemi-structural properties of external additives to relax the tolerance factor and optimize the optoelectronic performance of perovskite materials.</b>

scholarly journals Computational Study of Inverted All-Inorganic Perovskite Solar Cells Based on CsPbIxBr3-X Absorber Layer with Band Gap of 1.78 eV

2020 ◽  
Author(s):  
Nahuel Martínez ◽  
Carlos Pinzón ◽  
Guillermo Casas ◽  
Fernando Alvira ◽  
Marcelo Cappelletti
Keyword(s):  
Solar Cells ◽  
Band Gap ◽  
High Efficiency ◽  
Defect Density ◽  
Computational Study ◽  
Perovskite Solar Cells ◽  
Absorber Layer ◽  
Inorganic Materials ◽  
Tandem Solar Cells ◽  
Inorganic Perovskite

All-inorganic perovskite solar cells (PSCs) with inverted p-i-n configuration have not yet reached the high efficiency achieved in the normal n-i-p architecture. However, the inverted all-inorganic PSC are more compatible with the fabrication of tandem solar cells. In this work, a theoretical study of all-inorganic PSCs with inverted structure ITO/HTL/CsPbI<sub>x</sub>Br<sub>3</sub>−x/ETL/Ag, has been performed by means of computer simulation. Four p‐type inorganic materials (NiO, Cu<sub>2</sub>O, CuSCN and CuI) and three n-type inorganic materials (ZnO, TiO<sub>2</sub> and SnO<sub>2</sub>) were used as hole and electron transport layers (HTL and ETL), respectively. A band gap of 1.78 eV was used for the CsPbI x Br<sub>3</sub>−x perovskite layer. The simulation results allow identifying that CuI and ZnO are the most appropriate materials as HTL and ETL, respectively. Additionally, optimized values of thickness, acceptor density and defect density in the absorber layer have been obtained for the ITO/CuI/CsPbI x Br<sub>3</sub>−x /ZnO/Ag, from which, an optimum efficiency of 21.82% was achieved. These promising theoretical results aim to improve the manufacturing process of inverted all-inorganic PSCs and to enhance the performance of perovskite–perovskite tandem solar cells. <br>

Band gap fluctuations in Cu(In,Ga)Se2 thin films

2005 ◽  
Vol 865 ◽  
Author(s):  
Julian Mattheis ◽  
Thomas Schlenker ◽  
Martin Bogicevic ◽  
Uwe Rau ◽  
Jürgen H. Werner
Keyword(s):  
Thin Films ◽  
Solar Cells ◽  
Band Gap ◽  
Open Circuit Voltage ◽  
Band Gap Energy ◽  
Open Circuit ◽  
Measured Absorption ◽  
Alloy Disorder ◽  
Gallium Content ◽  
Forbidden Gap

AbstractA simple statistical model describes measured absorption and photoluminescence data of Cu(In1-x, Gax)Se2 thin films. The broadening of the transition peak in the absorption spectra stems from band gap fluctuations. The extent of the spatial inhomogeneities as expressed in the standard deviation Eg μ reaches a maximum of Eg μ = 90 meV for films with equal amounts of indium and gallium, indicating alloy disorder as one possible source of the band gap fluctuations. The fluctuations observed lead to a decrease δVOC of the maximum possible open-circuit voltage VOC of almost 150 mV. However, the experimentally measured, low VOC of solar cells with high gallium content cannot be explained by band gap fluctuations alone. Consequently, our analysis suggests that the dominant recombination process in Cu(In1-x, Gax)Se2 thin film solar cells with high gallium content is not governed by the band gap energy, but is more likely due to deep levels within the forbidden gap.

Controlling the Band Gap to Improve Open-Circuit Voltage in Metal Chalcogenide based Perovskite Solar Cells

2016 ◽  
Vol 215 ◽  
pp. 374-379 ◽  
Author(s):  
Meng Yuan ◽  
Xiaoman Zhang ◽  
Jun Kong ◽  
Wenhui Zhou ◽  
Zhengji Zhou ◽  
...  
Keyword(s):  
Solar Cells ◽  
Band Gap ◽  
Open Circuit Voltage ◽  
Perovskite Solar Cells ◽  
Open Circuit ◽  
Metal Chalcogenide
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