High irradiance performance of metal halide perovskites for concentrator photovoltaics (vol 3, pg 855, 2018)
NATURE ENERGY 3:11 (2018) 1013-1013
Atomic Layer Deposited Electron Transport Layers in Efficient Organometallic Halide Perovskite Devices
MRS Advances 3:51 (2018) 3075-3084
Abstract:
Copyright © Materials Research Society 2018Â. Amorphous TiO2 and SnO2 electron transport layers (ETLs) were deposited by low-Temperature atomic layer deposition (ALD). Surface morphology and x-ray photoelectron spectroscopy (XPS) indicate uniform and pinhole free coverage of these ALD hole blocking layers. Both mesoporous and planar perovskite solar cells were fabricated based on these thin films with aperture areas of 1.04 cm2for TiO2 and 0.09 cm2and 0.70 cm2for SnO2. The resulting cell performance of 18.3 % power conversion efficiency (PCE) using planar SnO2 on 0.09 cm2and 15.3 % PCE using mesoporous TiO2 on 1.04 cm2active areas are discussed in conjunction with the significance of growth parameters and ETL composition.Cubic or orthorhombic? Revealing the crystal structure of metastable black-phase CsPbI3 by theory and experiment
ACS Energy Letters American Chemical Society 3 (2018) 787-1794
Abstract:
Room-temperature films of black-phase caesium lead iodide (CsPbI3) are widely thought to be trapped in a cubic perovskite polymorph. Here, we challenge this assumption. We present structural refinement of room temperature black-phase CsPbI3 in an orthorhombic polymorph. We demonstrate that this polymorph is adopted by both powders and thin-films of black-phase CsPbI3, fabricated either by high- or low-temperature processes. We perform electronic band structure calculations for the orthorhombic polymorph and find agreement with experimental data and close similarities with orthorhombic methylammonium lead iodide. We investigate the structural transitions and thermodynamic stability of the various polymorphs of CsPbI3, and show that the orthorhombic polymorph is the most stable among its other perovskite polymorphs, but it remains less stable than the yellow non-perovskite polymorph.Highly crystalline methylammonium lead tribromide perovskite films for efficient photovoltaic devices
ACS Energy Letters American Chemical Society 3:6 (2018) 1233−1240
Abstract:
The rise of metal-halide perovskite solar cells has captivated the research community, promising to disrupt the current energy landscape. While a sizable percentage of the research done on this class of materials has been focused on the neat and iodide-rich perovskites, bromide-based perovskites can deliver substantially higher voltages because of their relatively wide band gaps of over 2 eV. The potential for efficient, high-voltage devices makes materials such as these incredibly attractive for multijunction photovoltaic applications. Here, we use the acetonitrile/methylamine solvent system to deposit smooth, highly crystalline films of CH3NH3PbBr3. By using choline chloride as a passivating agent for these films, we achieve photoluminescence quantum efficiencies of up to 5.5% and demonstrate charge-carrier mobilities of 17.8 cm2/(V s). Incorporating these films into photovoltaic devices, we achieve scanned power conversion efficiencies of up to 8.9%, with stabilized efficiencies of 7.6%, providing a simple route to realizing efficient, high-voltage CH3NH3PbBr3 planar-heterojunction devices.Impact of Bi3+ Heterovalent Doping in Organic-Inorganic Metal Halide Perovskite Crystals.
Journal of the American Chemical Society 140:2 (2018) 574-577