Dear Hong,

Adding to Tanuj, investigating the materials from the ITO may difficult but not impossible. You can measure the reflectance of the structure as a function of wavelength of the incident radiation. The reflection coefficient is very sensitive to the the dielectric constant and the conductivity of the materials and the dielectric properties mismatch on the interfaces of the different materials.

More important is to measure the electroluminescence of the material. The perovskite is a direct band gap and is an effective radiator. The radiated light wavelength and intensity are very sensitive to  structural changes of the material especially the lifetime of the minority charges and the energy band structure. In this test one needs to operate the solar cell as A LED.

This in addition to monitoring the Solar cell parameters with time. The solar cell parameters are indicators for electronic properties of materials.

wish you success

Most analysis tools are based on surface techniques, so it will be very difficult to analyze your encapsulated structure. Can you analyze the structure before you cap it with ITO? Also, which film in the heterostructure are you interested in analyzing the degradation for? Otherwise your best option is to measure the device characteristics of the structure and compare how it degrades, and then indirectly relate to the material degradation.

Dear Hong,

Adding to Tanuj, investigating the materials from the ITO may difficult but not impossible. You can measure the reflectance of the structure as a function of wavelength of the incident radiation. The reflection coefficient is very sensitive to the the dielectric constant and the conductivity of the materials and the dielectric properties mismatch on the interfaces of the different materials.

More important is to measure the electroluminescence of the material. The perovskite is a direct band gap and is an effective radiator. The radiated light wavelength and intensity are very sensitive to  structural changes of the material especially the lifetime of the minority charges and the energy band structure. In this test one needs to operate the solar cell as A LED.

This in addition to monitoring the Solar cell parameters with time. The solar cell parameters are indicators for electronic properties of materials.

wish you success

Dear Tanuj Trivedi,

Thanks your help. I mainly focus on the degradation of perovskite film.

Dear Prof. Abdelhalim Zekry,

Thanks for your help.  Measure the reflectance of the sealed perovskite-based device is a very good tool to detect the change of perovskite film. Measure the electroluminescence of the material is also a very good method. However, our sealed device may degrade rapidly during the measurement of electroluminescence, which may be caused by the rising temperature during the measurement. BTW, can I use the PL transient photocurrent/photovoltage decay to check the change of charge transport and recombination time constants (indirect reflect the perovskite degradation?)?

Hong

Dear Hong ZHANG, I think maybe you can peel the upperlayers off if the device structure can be sacrificed，or etch the glass and ito off by ion or laser or some other effective method.

Dear Hong,

Yes you can use all of them to trace the degradation of the material with time. ALL THESE PARAMETERS ARE SENSITIVE  TO THE PERVOSKITE ELECTRONIC PERFORMANCE SPECIALLY THE THE DEFECTS THAT LEAD TO HIGH RECOMBINATION RATE. The photo open circuit voltaic decay may be the most suitable parameter as it is the combined effect of the the photocurrent and the dark current.

For more information please see the link:http://pubs.acs.org/doi/abs/10.1021/jz502703p

wish you success. 

Thanks, Ye. It is a good way to analysis the precise component of the degraded perovskite and find out the cause.

Dear Prof. Abdelhalim Zekry,

Very useful information. Thanks for your help. I will try it in my experiment.

Hong