“…Rapidly growing applications of CdZnTe as a material suitable for X-ray and γ-ray detector fabrication − and for high-efficiency solar cells , have introduced the urgent need for characterization of photocarrier properties and their associated solid-state transport parameters, including their spatial distributions in wafer substrates, which affect charge transport and limit the performance of optoelectronic devices. Most popular diagnostic methods in use are current deep-level transient spectroscopy (I-DLTS), transient current technique (TCT), current and capacitance vs voltage ( I – V and C – V ) measurements, γ-ray spectroscopy, Hall measurements, and optical and thermal measurements. − Beyond those methodologies, photocarrier radiometry (PCR) is a nondestructive and noncontacting spectrally gated frequency-domain dynamic semiconductor photoluminescence (PL) diagnostic modality, which allows for the simultaneous nondestructive determination of electronic transport parameters in semiconductor substrates and devices. − Subsequently, lock-in carrierography (LIC) was introduced as a near-infrared (NIR) imaging extension of PCR, aimed at constructing quantitative images of carrier transport parameters. − Next, two-beam heterodyne LIC (HeLIC) was introduced to address the need for high-frequency photocarrier excitation, eliciting fast enough signal responses required to measure short recombination lifetimes and other fast photocarrier relaxation processes. HeLIC was developed to allow high-frequency dynamic imaging of optoelectronic material and device properties, which require sampling rates orders of magnitude higher than those achievable by the frame rates of today’s fastest NIR camera technologies. − Very recently, heterodyne PCR (HePCR) proved to be very sensitive to photocarrier emission/capture processes out of, and into, band-gap defect and impurity states: a newly discovered HePCR phenomenon giving rise to a frequency-domain heterodyne signal amplitude depression (“dip” or “notch”) accompanied by a 180° phase transition was attributed to a nonlinear kinetic mechanism of laser-excited harmonic carrier density waves (CDW) interacting with trap or defect states in Si wafers .…”