Objectives

Specific Objectives:

• The outdoor investigation of degradation mechanisms of different structure perovskites and perovskites on silicon tandems at different ambient conditions through the simultaneous collection of high quality, high resolution IV measurements from PV cells installed in the field and the collection of high-resolution environmental and spectral data for evaluating the spectral performance. These measurements will reveal the correlation between the performance degradation outdoors of the different structure perovskite and perovskite on silicon cells with the environmental conditions on a seasonal basis.


• The failures evolution of the different perovskite and perovskite on silicon tandem cells with advanced optoelectronic techniques such as Dark Lock-in Thermography (DLIT), Lock-in Thermography (LIT), Light Beam Induced Current (LBIC), spatially-resolved Electroluminescence (EL) and Photoluminescence (PL) that will be built for that purpose. The indoor examination of the cells with those techniques will provide information about the changes in the efficiency map of the cells at regular time intervals after outdoor exposure.


• Addressing the challenges during indoor and outdoor characterization of the perovskites and perovskite on silicon tandem cells. Particularly, examination of the ideal voltage/light bias and voltage bias conditions should exist during the quantum efficiency and current-voltage measurements respectively will be undertaken. Those investigations are essential for the accurate measurements of the quantum efficiency and the power conversion efficiency of the perovskites-based cells.


• The investigation of carrier dynamics and chemical imaging of the perovskite-based cells before and after degradation in an attempt to understand the carrier losses and obtain the various decomposition products due to degradation. understanding of the degradation mechanisms of solar cells in an attempt to provide feedback for more stable solar cells. This can be achieved using Ultrafast and Resonance Raman spectroscopy methods before and after the outdoor exposure of cells at regular time intervals.


• The correlation between the microscopic investigations of failures with the performance degradation of perovskites-based cells. The microscopic investigation of failures can be achieved with Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy dispersive X-ray spectroscopy (EDX), X-ray Photoelectron Microscopy (XPS). The structural characterization in combination with the advanced indoor and outdoor testing will provide a deep insight towards the material aspects of cells thus contributing to their stability and efficiency.

Technological objectives of the project include:

• The setup of DLIT, LIT, LBIC, spatially resolved EL and PL. All the aforementioned methods monitor essential electrical parameters of PV cell thus allowing a direct evaluation of a cell or mini-module quality. The aforementioned methods are the most important tools for the investigation of the defect affected areas.


• The indoor characterization of cells with I-V, DLIT, LIT, LBIC, EL, PL, Capacitance-Voltage, Fourier transform infrared spectroscopy, Ultrafast and Raman spectroscopy and in cases where is needed with methods of SEM, TEM, EDX and XPS. The numerous methods will target to better fundamental understanding of the physical mechanisms involved in perovskites cells failure.


• The spectral characterization of cells using quantum eficciency measurements


• The development of testing protocols for current-voltage and quantum efficiency measurements such as perovskites, perovskite tandems. A well-defined methodology for performing accurate performance and quantum efficiency measurements in those cells is absent and should be taken into consideration.
  
  
• The collection of real side-by-side outdoor performance data of cells at different ambient conditions alongside with the collection of environmental and spectral measurements.


• The evaluation of uncertainties in the testing methodology and infrastructure. This is required for the correct implementation of measurements using the new infrastructure.