text: Knowledge of charge carrier mobility in semiconductors is important for understanding the electronic and materials properties of a system. It is also valuable in device design and optimization. This is particularly true for thin film solar cells and thin film transistors, where charge extraction and amplification, respectively, are highly dependent upon mobility. TRMC has been used to study electron and hole dynamics in hydrogenated amorphous silicon, organic semiconductors, metal halide perovskites, metal oxides, dye sensitized systems, quantum dots, carbon nanotubes, chalcogenides, metal organic frameworks, and the interfaces between various systems.
  Because charges are normally generated using a green (~2.3 eV) or ultraviolet (~3 eV) laser, this restricts materials to those with comparable or smaller bandgaps. The technique is hence well suited to the study of solar absorbers, but not to wide bandgap semiconductors such as metal oxides.    
  While it is very similar, and has the same dimensions, the parameter  is not the same a charge carrier mobility.  contains contributions from both holes and electrons, which cannot conventionally be resolved using TRMC. This is in contrast to Hall Measurements or transistor measurements, where hole and electron mobility can easily be separated. Additionally, the mobility is not directly extracted from the measurements, it is measured multiplied by the carrier generation yield, . The carrier generation yield is the number of electron hole pairs generated per absorbed photon. Because some absorbed photons can lead to bound neutral excitons, not all absorbed photons will lead to detectable free carriers. This can make interpretation of  more complicated than mobility. However, generally both mobility and  are parameters which one wishes to maximize when developing solar cells.     
  As a time-resolved technique, TRMC also provides information on the timescale of carrier recombination in solar cells. Unlike time resolved photoluminescence measurements, TRMC is not sensitive to the lifetime of excitons.