Firstly, I'm interested in luminesence techniques. To the best of my knowledges, PL kinetics measurements can point out direct or indirect characters of the carriers, whereas pumping power dependence of the PL peak position can provide information about existing type-I or type-II heterostructure. If it is correct, I want more detailed information. Also I'm interested in alternative methods (may be electrical or so on) if any.
The direct or indirect character of the transition can be determined from the wavelength (photon energy) dependence of the excitation efficiency. It can be investigated also by electrical measurement, for example photo-current versus excitation photon energy dependence. The direct optical transition has much higher probability, since there are no phonons involved in the process. The simple picture is complicated by the presence of dopants atoms and possible point defects in the crystalline semiconductor material, I was using these techniques, but you can find good review papers on the topic in the literature from authors specialized in this field.
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