Effect of Mesostructured Layer upon Crystalline Properties and Device Performance on Perovskite Solar Cells.
One of the most fascinating characteristics of perovskite solar cells (PSCs) is the retrieved obtainment of outstanding photovoltaic (PV) performances withstanding important device configuration variations. Here we have analyzed CH3NH3PbI3-xClx in planar or in mesostructured (MS) configurations, employing both titania and alumina scaffolds, fully infiltrated with perovskite material or presenting an overstanding layer. The use of the MS scaffold induces to the perovskite different structural properties, in terms of grain size, preferential orientation, and unit cell volume, in comparison to the ones of the material grown with no constraints, as we have found out by X-ray diffraction analyses. We have studied the effect of the PSC configuration on photoinduced absorption and time-resolved photoluminescence, complementary techniques that allow studying charge photogeneration and recombination. We have estimated electron diffusion length in the considered configurations observing a decrease when the material is confined in the MS scaffold with respect to a planar architecture. However, the presence of perovskite overlayer allows an overall recovering of long diffusion lengths explaining the record PV performances obtained with a device configuration bearing both the mesostructure and a perovskite overlayer. Our results suggest that performance in devices with perovskite overlayer is mainly ruled by the overlayer, whereas the mesoporous layer influences the contact properties.
†Center for Bio-Molecular Nanotechnology, Fondazione Istituto Italiano di Tecnologia, Via Barsanti, 73010 Arnesano, Lecce, Italy.|‡Istituto di nanotecnologia CNR Nanotec, Via Arnesano 16, 73100 Lecce, Italy.
Andrea
A
Listorti
§Photovoltaic and Optoelectronic Devices Group, Departament de Física, Universitat Jaume I, 12071 Castelló, Spain.
Emilio J
EJ
Juarez-Perez
∥Institut de Ciència de Materials de Barcelona, ICMAB-CSIC, Campus de la UAB, Cerdanyola del Vallès, Barcelona 08193, Spain.
Carlos
C
Frontera
†Center for Bio-Molecular Nanotechnology, Fondazione Istituto Italiano di Tecnologia, Via Barsanti, 73010 Arnesano, Lecce, Italy.|⊥Dept. of Physics, Politecnico di Milano, Piazza Leonardo da Vinci 32, 20133 Milano, Italy.
Vittoria
V
Roiati
§Photovoltaic and Optoelectronic Devices Group, Departament de Física, Universitat Jaume I, 12071 Castelló, Spain.|¶Grupo de Diseño de Productos y Procesos, Departamento de Ingeniería Química, Universidad de los Andes, Cr 1 aEste 19A-40, 110111 Bogotá, Colombia.
Laura
L
Garcia-Andrade
‡Istituto di nanotecnologia CNR Nanotec, Via Arnesano 16, 73100 Lecce, Italy.|∇Dipartimento di Matematica e Fisica "E. de Giorgi", Università del Salento, Via Arnesano 16, 73100, Lecce Italy.
Silvia
S
Colella
‡Istituto di nanotecnologia CNR Nanotec, Via Arnesano 16, 73100 Lecce, Italy.
Aurora
A
Rizzo
¶Grupo de Diseño de Productos y Procesos, Departamento de Ingeniería Química, Universidad de los Andes, Cr 1 aEste 19A-40, 110111 Bogotá, Colombia.
Pablo
P
Ortiz
§Photovoltaic and Optoelectronic Devices Group, Departament de Física, Universitat Jaume I, 12071 Castelló, Spain.
Ivan
I
Mora-Sero
D017610:Calcium Compounds / Q000737:chemistry*; D003460:Crystallization; D008855:Microscopy, Electron, Scanning; D010087:Oxides / Q000737:chemistry*; D012993:Solar Energy; D014025:Titanium / Q000737:chemistry*
D017610:Calcium Compounds; D010087:Oxides; C059910:perovskite; D014025:Titanium
Diffusion Length; Mesostructure; Perovskite solar cells; Photoinduced Absorption; Time-Resolved Photoluminescence; X-ray Diffraction