Comparison of Recombination Dynamics in CH3NH3PbBr3 and CH3NH3PbI3 Perovskite Films: Influence of Exciton Binding Energy

Hou

Advanced Energy Materials

et al. 2016

spectral range for singe junction solar cells, and according to the Shockley-Queisser model the photocurrent is expected to be below 9.7 mA cm −2 . [2] However, a relatively high V oc of 1.4-1.5 V was reported, which makes this material system a great candidate for applications such as tandem configuration or other systems requiring spectral splitting. [2][3][4][5][6][7] Significant efforts were undertaken to investigate and optimize the V oc of CH 3 NH 3 PbBr 3 solar cells. [2][3][4][5][6][7][8][9] Engineering advanced hole transport layers (HTL) such as carbon nanotubes, [2] 2,2′,7,7′-tetrakis(N,Ndi-p-methoxyphenyl-amine)-9,9′-spirobifluorene (spiro-OMeTAD), [5,7] poly (indenofluoren-8-triarylamine) (PIF8-TAA), [3,4] and 4,4-bis(N-carbazolyl)-1,1-biphenyl (CBP) [6] resulted in V oc within a range of 1.4-1.5 V for solution-processed perovskite solar cells. Sheng et al. demonstrated a high V oc of 1.45 V using the architecture TiO 2 / CH 3 NH 3 PbBr 3 /spiro-OMeTAD via a vaporassisted depositon. [7] Kim et al. modified the TiO 2 surfaces with carboxyl groups and employed no HTL for CH 3 NH 3 PbBr 3 solar cells, producing a V oc of 1.37 V. [8] Dymshits et al. reported a V oc of 1.35 V for Al 2 O 3 /CH 3 NH 3 PbBr 3 perovskite solar cells without HTL. [9] These studies focused more on the V oc improvement via interface engineering and via optimizing the CH 3 NH 3 PbBr 3 film quality. Despite significant progress toward unraveling the V oc limitation of CH 3 NH 3 PbBr 3 solar cells, the limiting V oc (V oc,rad ) is still unknown to the best of our knowledge. Besides, Perovskite solar cells based on CH

Section: Resultsmentioning

confidence: 99%

Exploring the Limiting Open‐Circuit Voltage and the Voltage Loss Mechanism in Planar CH₃NH₃PbBr₃ Perovskite Solar Cells

Hou

Advanced Energy Materials

et al. 2016

Advanced Energy Materials

“…Common Requirements [46,208] Copyright 2016, Nature Magneto-optical absorption spectroscopy [69] Polycrystalline 3D 22 Magneto-optical absorption spectroscopy [71] Polycrystalline 3D 2 Spectroscopic ellipsometry [66] Polycrystalline 3D 13 Optical absorption [72] Polycrystalline 3D 7 Electroabsorption Spectroscopy [8] Polycrystalline 3D 12 Magneto-optical absorption spectroscopy [73] CH3NH3PbBr3 Microcrystalline 3D 84 X-ray spectroscopy/Temperature dependent PL [74] Nanoparticle 3D 320 X-ray spectroscopy [74] Polycrystalline 3D 76 Magnetoabsorption [71] Polycrystalline 3D 40 Optical absorption [72] CH3NH3PbI3-xClx Polycrystalline 3D 55 Optical absorption [67] Polycrystalline 3D 10 Magneto-optical absorption spectroscopy [73] CH(NH2)2PbI3 Polycrystalline 3D 10 Magneto-optical absorption spectroscopy [73] CH(NH2)2PbBr3 Polycrystalline 3D 24 Magneto-optical absorption spectroscopy [73] (C9H19NH3)2PbI4 n/a 2D > 330 Temperature dependent PL [75] (C10H21NH3)2PbI4 Single crystal 2D 370 Optical absorption [76] (C6H5C2H4NH3)2PbI4 Polycrystalline 2D 350 Optical absorption [77] (NH2C(I)=NH2)3PbI5 n/a 1D > 410 Optical absorption [75] (CH3NH3)4PbI6•2H2O n/a 0D 545 Optical absorption [75] Eb: Exciton binding energy, PL: Photoluminescence Reproduced with permission. [98] Copyright 2014, Nature Publishing Group.…”

Section: Light Harvester Light Emittermentioning

confidence: 99%

Hybrid Perovskites: Effective Crystal Growth for Optoelectronic Applications

Jeon

Kim

Yoon

et al. 2017

Outstanding material properties of organic-inorganic hybrid perovskites have triggered a new research insight into the next-generation solar cells. Moreover, a wide range of controllable properties of hybrid perovskites particularly depending on crystal growth conditions enables versatile high performance optoelectronic devices such as light-emitting diodes, photodetectors and lasers beyond solar cells. This invited review article highlights recent progress of the crystallization strategies of organic-inorganic hybrid perovskites for effective light harvester or light emitter. In the first part, fundamental background on the perovskite crystalline structures and relevant optoelectronic properties such as optical band-gap, electron-hole behavior and energy band alignment are introduced. In the second part, detailed overview of the effective crystallization methods for perovskites, including thermal treatment, additives, solvent mediator, laser irradiation, nanostructure, crystal dimensionality and so on, is described to offer a comprehensive correlation among perovskite processing conditions, crystalline morphology and relevant device performances. Finally, future research direction is proposed to overcome current practical bottlenecks and move towards reliable high performance perovskite optoelectronic applications.3

“…The reduction of charge recombination in bulk film requires high quality perovskite film with full surface coverage [26][27][28], large crystal size [15,29,30] and low defect density [31][32][33]. The post-treatment using a strong Lewis base is a very effective method to improve the quality of lead halide perovskite films [34][35][36][37][38][39][40][41][42].…”

Section: Introductionmentioning

confidence: 99%

A Feasible and Effective Post-Treatment Method for High-Quality CH3NH3PbI3 Films and High-Efficiency Perovskite Solar Cells

Jiang

et al. 2018

Crystals

Abstract:The morphology control of CH 3 NH 3 PbI 3 (MAPbI 3 ) thin-film is crucial for the high-efficiency perovskite solar cells, especially for their planar structure devices. Here, a feasible and effective post-treatment method is presented to improve the quality of MAPbI 3 films by using methylamine (CH 3 NH 2 ) vapor. This post-treatment process is studied thoroughly, and the perovskite films with smooth surface, high preferential growth orientation and large crystals are obtained after 10 s treatment in MA atmosphere. It enhances the light absorption, and increases the recombination lifetime. Ultimately, the power conversion efficiency (PCE) of 15.3% for the FTO/TiO 2 /MAPbI 3 /spiro-OMeTAD/Ag planar architecture solar cells is achieved in combination with this post-treatment method. It represents a 40% improvement in PCE compared to the best control cell. Moreover, the whole post-treatment process is simple and cheap, which only requires some CH 3 NH 2 solution in absolute ethanol. It is beneficial to control the reaction rate by changing the volume of the solution. Therefore, we are convinced that the post-treatment method is a valid and essential approach for the fabrication of high-efficiency perovskite solar cells.