Carrier-Resolved Photo Hall Effect and the Parallel Dipole Line Hall System

Abstract

We recently reported carrier-resolved photo Hall (CRPH) effect $ technique^1 $ that enables us to extract remarkable amount of information from majority and minority carrier in semiconductors under light illumination such as their mobilities, photo-carrier density, recombination lifetime and diffusion lengths. This new technique extends the capability of the original Hall effect that only reveals majority carrier information (type, density and mobility). The CRPH technique also presents a more unified understanding in extracting the information from electronics materials combining electric, magnetic field and light excitation. This technique has been applied to high performance perovskite and kesterite solar materials. The technique is enabled by two new advances: a new formula that yields mobility difference from the conductivity and Hall coefficient curve with varying light intensity and the development of AC Hall technique using parallel dipole line system. We will discuss both development in more details and present several interesting CRPH studies in various materials. [1] O. Gunawan et. al., Nature 575, 151 (2019).