A laser terahertz emission microscope (LTEM) can be used for noncontact inspection to detect the waveforms of photoinduced terahertz emissions from material devices. In this study, we experimentally compared the performance of LTEM with conventional analysis methods, e.g.,electroluminescence (EL), photoluminescence (PL), and laser beam induced current (LBIC), as an inspection method for solar cells. The results showed that LTEM was more sensitive to the characteristics of the depletion layer of the polycrystalline solar cell compared with EL, PL,and LBIC and that it could be used as a complementary tool to the conventional analysis methods for a solar cell
Ryotaro Inoue, Kazuhisa Takayama, and Masayoshi Tonouchi
https://www.osapublishing.org/josab/abstract.cfm?URI=josab-26-9-A14
In this paper, the angular dependence of terahertz (THz) emission from semiconductor surfaces photoexcited by femtosecond optical pulses is reported. Time-domain waveforms of THz emission from (100) surfaces of semi-insulating gallium arsenide (𝑠𝑖-GaAs) andp-type indium arsenide (𝑝-InAs) are measured at various angles after careful suppression of the nonlinear optical rectification effect. THz emission angle-frequency patterns under focusing conditions of the excitation beam are regarded as radiation from an electric dipole moment located on the semiconductor surface. Based on the experimental results in the magnetic field parallel to the semiconductor surface, we discuss the ultrafast carrier dynamics on the surfaces of both semiconductors.
