Data for: Effect of bending test on the performance of CdTe solar cells on flexible ultra-thin glass produced by MOCVD
Description
The photovoltaic performance was measured by J-V under AM1.5G at 25 ⁰C following a 10 minutes light soak, using an ABET Technologies Sun 2000 Solar Simulator. The measurements were performed when the cell was in a planar state, and then when flexed to a 40 mm and subsequent 32 mm bend radius. After flexion the device was relaxed and measured flat. In addition, the sample was held at a bend radius of 32 mm for 168 hours with measurement at 0, 24, 48, 120, 144 and 168 hours. Again, the sample was measured flat before and after the bending test. Additionally, external quantum efficiency (EQE) and capacitance voltage (C-V) measurements were performed before and after 168 hours bending test. A Bentham PVE300 photovoltaic spectrometer was used for EQE measurements and a Solartron analytical modulab model 2100A was used for C-V measurements. Residual stress measurements were made with a Bruker D8 Discover X-ray diffraction system. The equipment was set up in a point mode with a polycapillary element and nickel filter. Scans were made with a 0.02° step size, at a time of 1 second per step. The scans were over the full 0−0.45 sin2(ψ) in both positive and negative ψ tilts to confirm the absence of shear stress. Peak evaluation was undertaken using the Pearson VII fitting and stresses were calculated using a normal stress model. The Diffrac, Leptos software was used to model the peaks, then the peak shift was changed to strain using the Poisson’s ratio of 0.2 and Young’s Modulus of 77000MPa. This data was then plotted with strain vs the sin2(ψ) value.