I am investigating an active photovoltaic material using time resolved photoluminescence measurements to find out the carrier lifetime of the material, and hence the diffusion length.
There are many PL peaks in it's spectrally resolved PL. Should I measure the lifetime using the band-to-band emission, or can I measure the lifetime of all the PL peaks (including defect-related PL emissions)?
What info does measuring the lifetime of a defect-related PL emission tell us?
Hi Helen
Do you have different materials in the structure?
If this is the case, I think you can use the peak related to the band to band recombination in the space charge region (or intrinsic part) since it defines the luminiscence extinction induced by the photovoltaic effects.
Hi Prof. Bouraoui,
The PL sample is simply the material deposited on a Silicon wafer with thermal oxide, so I will not be expecting luminescence due to photovoltaic effects.
Will performing PL studies on the p-n junction (p-type active material and the n-type partner) be different (or even preferred) from the PL studies done on just the p-type active layer?
If this is the case, can it also tell us something about how suitable the n-type partner material is at reducing interfacial recombination of the photogenerated carriers by looking at the dfiference of the PL measurements with and without the p-n junction formed?
Yes I guess
Stationery PL can also be helpful for a preliminary investigation by comparing the integrated intensity. You can gain information on whether the defects density has been reduced.
It depends on the nature of the material under investigation. Whether it us a semiconductor, organic or organometallic. It also depends on the energy levels of the excited state being involved in the charge generation.
I would rather think more of transient absorption. The former is highly liable to surrounding medium and the crystal surface nature, while the later reflects only the occupancy of the ground state levels.
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