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Large datasets are now ubiquitous as technology enables higher-throughput experiments, but rarely can a research field truly benefit from the research data generated due to inconsistent formatting, undocumented storage or improper dissemination. Here we extract all the meaningful device data from peer-reviewed papers on metal-halide perovskite solar cells published so far and make them available in a database. We collect data from over 42,400 photovoltaic devices with up to 100 parameters per device. We then develop open-source and accessible procedures to analyse the data, providing examples of insights that can be gleaned from the analysis of a large dataset. The database, graphics and analysis tools are made available to the community and will continue to evolve as an open-source initiative. This approach of extensively capturing the progress of an entire field, including sorting, interactive exploration and graphical representation of the data, will be applicable to many fields in materials science, engineering and biosciences.

In this paper, co-evaporation of Cu(In,Ga)Se 2 (CIGS) in an inline single-stage process is used to fabricate solar cell devices with up to 18.6% conversion efficiency using a CdS buffer layer and 18.2% using a Zn 1 −x Sn x O y Cd-free buffer layer. Furthermore, a 15.6-cm 2 mini-module, with 16.8% conversion efficiency, has been made with the same layer structure as the CdS baseline cells, showing that the uniformity is excellent. The cell results have been externally verified. The CIGS process is described in detail, and material characterization methods show that the CIGS layer exhibits a linear grading in the [Ga]/([Ga]+[In]) ratio, with an average [Ga]/([Ga]+[In]) value of 0.45. Standard processes for CdS as well as Cd-free alternative buffer layers are evaluated, and descriptions of the baseline process for the preparation of all other steps in theÅngström Solar Center standard solar cell are given.

Zinc tin oxide (Zn(1-x)Sn(x)O(y)) has been proposed as an alternative buffer layer material to the toxic, and light narrow-bandgap CdS layer in CuIn(1-x),Ga(x)Se(2) thin film solar cell modules. In this present study, synchrotron-based soft X-ray absorption and emission spectroscopies have been employed to probe the densities of states of intrinsic ZnO, Zn(1-x)Sn(x)O(y) and SnO(x) thin films grown by atomic layer deposition. A distinct variation in the bandgap is observed with increasing Sn concentration, which has been confirmed independently by combined ellipsometry-reflectometry measurements. These data correlate directly to the open circuit potentials of corresponding solar cells, indicating that the buffer layer composition is associated with a modification of the band discontinuity at the CIGS interface. Resonantly excited emission spectra, which express the admixture of unoccupied O 2p with Zn 3d, 4s, and 4p states, reveal a strong suppression in the hybridization between the O 2p conduction band and the Zn 3d valence band with increasing Sn concentration.

A new atomic layer deposition process was developed for deposition of Zn-Sn-O buffer layers for Cu(In,Ga)Se 2 solar cells with tetrakis(dimethylamino) tin, Sn(N(CH 3 ) 2 ) 4 , diethyl zinc, Zn(C 2 H 5 ) 2 , and water, H 2 O. The new process gives good control of thickness and [Sn]/([Sn]+[Zn]) content of the films. The Zn-Sn-O films are amorphous as found by grazing incidence X-ray diffraction, have a high resistivity, show a lower density compared with ZnO and SnO x , and have a transmittance loss that is smeared out over a wide wavelength interval. Good solar cell performance was achieved for a [Sn]/([Sn]+[Zn]) content determined to be 0.15-0.21 by Rutherford backscattering. The champion solar cell with a Zn-Sn-O buffer layer had an efficiency of 15.3% (V oc =653mV, J sc (QE)=31.8mA/cm 2 , and FF=73.8%) compared with 15.1% (V oc =663mV, J sc (QE)=30.1mA/cm 2 , and FF=75.8%) of the best reference solar cell with a CdS buffer layer. There is a strong light-soaking effect that saturates after a few minutes for solar cells with Zn-Sn-O buffer layers after storage in the dark. Stability was tested by 1000h of dry heat storage in darkness at 85 C, where Zn-Sn-O buffer layers with a thickness of 76nm retained their initial value after a few minutes of light soaking.