Carrier Lifetime Measurements in Semiconductors through the Microwave Photoconductivity Decay Method

Abstract

This work presents a protocol employing the microwave photoconductivity decay (μ-PCD) for measurement of the carrier lifetime in semiconductor materials, especially SiC. In principle, excess carriers in the semiconductor generated via excitation recombine with time and, subsequently, return to the equilibrium state. The time constant of this recombination is known as the carrier lifetime, an important parameter in semiconductor materials and devices that requires a noncontact and nondestructive measurement ideally achieved by the μ-PCD. During irradiation of a sample, a part of the microwave is reflected by the semiconductor sample. Microwave reflectance depends on the sample conductivity, which is attributed to the carriers. Therefore, the time decay of excess carriers can be observed through detection of the reflected microwave intensity, whose decay curve can be analyzed for estimation of the carrier lifetime. Results confirm the suitability of the μ-PCD protocol in measuring the carrier lifetime in semiconductor materials and devices.

The Hump Phenomenon and Instability of Oxide TFT Were Eliminated by Interfacial Passivation and UV + Thermal Annealing Treatment

“…At this point, the trapping process is greatly impeded so that the drift velocity gradually decreases and finally approaches zero. In summary, by parameter fitting, the probability of carrier capture or release is lower for TFT-4 and the range of fluctuations in channel carrier concentration is smaller, which also explains the reason for its superior stability. , …”

“…In summary, by parameter fitting, the probability of carrier capture or release is lower for TFT-4 and the range of fluctuations in channel carrier concentration is smaller, which also explains the reason for its superior stability. 19,20 The characteristics of the TFT-CV are often used to extract and analyze the density of states (DOS) of devices. In this paper, a simple method is used to extract the DOS, which is only used for semiquantitative analysis between the same set of samples, avoiding various complicated extraction methods.…”

Analysis of defects dominating carrier recombination in CeO2 single crystal for photocatalytic applications

“…To measure the TR-PL separately, a 565 nm (2.19 eV) band-pass filter (w/ 565 BPF) with a center wavelength of 565 nm and a peak transmission width of 133 nm (498.5-631.5 nm, 1.96-2.49 eV) was positioned between the 355 nm long-pass filer and the photomultiplier. For the µ-PCD measurements, a custom setup described in detail in a previous report was used [30]. Microwaves generated by a Gunn diode at a frequency of 10 GHz with an output power of 50 mW were irradiated through a waveguide on the unexcited side of the sample as a measurement probe [22-24, 26, 31].…”

Effect of dislocations on carrier recombination and photoelectrochemical activity in polished and unpolished TiO2 and SrTiO3 crystals

“…A custom setup discussed in detail in a previous report 64 was used for μ-PCD measurements. Yttrium aluminum garnet (YAG) lasers with wavelengths of 266 and 355 nm and pulse width of 1 ns were used as excitation light sources (FTSS 266-200 and FTSS 355-50, CryLas).…”