Doping of the lead telluride and related alloys with the group III impurities results in appearance of the unique physical features of a material, such as persistent photoresponse, enhanced responsive quantum efficiency (up to 100 photoelectrons/incident photon), high radiation hardness and many others. We present the physical principles of operation of the photodetecting devices based on the group III-doped IV-VI including the possibilities of a fast quenching of the persistent photoresponse, construction of the focal-plane array, and others. We report on the performance of lead telluride-based single direct detectors. The optical NEP on the order of 10-19 W/Hz1/2 at T=1.57 K has been demonstrated at the wavelength of 350 m. The advantages of terahertz photodetecting systems based on the group III-doped IV-VI are summarized.
Doping of the lead telluride and related alloys with the group III impurities results in appearance of the unique physical
features of a material, such as persistent photoresponse, enhanced responsive quantum efficiency (up to 100
photoelectrons/incident photon), radiation hardness and many others. We present the physical principles of operation of
the photodetecting devices based on the group III-doped IV-VI including the possibilities of a fast quenching of the
persistent photoresponse, construction of the focal-plane array, new readout technique, and others. The advantages of
infrared photodetecting systems based on the group III-doped IV-VI in comparison with the modern photodetectors are
summarized. The spectra of the persistent photoresponse have not been measured so far because of the difficulties with
screening the background radiation. We report on the observation of strong persistent photoconductivity in
Pb0.75Sn0.25Te(In) under the action of monochromatic submillimeter radiation at wavelengths of 176 and 241 microns.
The sample temperature was 4.2 K, the background radiation was completely screened out. The sample was initially in
the semiinsulating state providing dark resistance of more than 100 GOhm. The responsivity of the photodetector is by
several orders of magnitude higher than in the state of the art Ge(Ga). The red cut-off wavelength exceeds the upper limit
of 220 microns observed so far for the quantum photodetectors in the uniaxially stressed Ge(Ga). It is possible that the
photoconductivity spectrum of Pb1-xSnxTe(In)covers all the submillimeter wavelength range.
Doping of the lead telluride and related alloys with the group III impurities results in appearance of the unique physical
features of a material, such as persistent photoresponse, enhanced responsive quantum efficiency (up to 100
photoelectrons/incident photon), radiation hardness and many others. We present the physical principles of operation of
the photodetecting devices based on the group III-doped IV-VI including the possibilities of a fast quenching of the
persistent photoresponse, construction of the focal-plane array, new readout technique, and others. The advantages of
infrared photodetecting systems based on the group III-doped IV-VI in comparison with the modern photodetectors are
summarized. The spectra of the persistent photoresponse have not been measured so far because of the difficulties with
screening the background radiation. We report on the observation of strong persistent photoconductivity in
Pb0.75Sn0.25Te(In) under the action of monochromatic submillimeter radiation at wavelengths of 176 and 241 microns.
The sample temperature was 4.2 K, the background radiation was completely screened out. The sample was initially in
the semiinsulating state providing dark resistance of more than 100 GOhm. The responsivity of the photodetector is by
several orders of magnitude higher than in the state of the art Ge(Ga). The red cut-off wavelength exceeds the upper limit
of 220 microns observed so far for the quantum photodetectors in the uniaxially stressed Ge(Ga). It is possible that the
photoconductivity spectrum of Pb1-xSnxTe(In)covers all the submillimeter wavelength range.
The work deals with studies of the grain size and surface state effect on photoelectric and transport properties of
PbTe(In) films in the temperature range from 4.2 K up to 200 K under irradiation of a blackbody source and terahertz
laser pulses. The PbTe(In) films were deposited on insulating substrates kept at the temperatures TS equal to -120 (see manuscript)
250C. AFM, SEM, Auger spectroscopy and X-ray diffraction were used to study the film microstructure. Increase of the
TS value led to mean grain size growth from 60 up to 300 nm. All films had a column-like structure with the columns
nearly perpendicular to the substrate plane. It is shown that microstructure of the films strongly affects the
photoconductivity character in the terahertz region of the spectrum. Positive persistent photoresponse is observed at low
temperatures in the polycrystalline films. For these films transport and photoelectric properties are determined by the
grain volume and impurity state specifics. Nanocrystalline films have all features of non-homogeneous systems with
band modulation. For these films only negative photoconductivity is observed in the whole temperature range. Possible
mechanisms of the photoresponse formation are discussed.
Doping of the lead telluride and related alloys with the group III impurities results in appearance of the unique physical
features of a material, such as persistent photoresponse, enhanced responsive quantum efficiency (up to 100
photoelectrons/incident photon), radiation hardness and many others. We present the physical principles of operation of
the photodetecting devices based on the group III-doped IV-VI including the possibilities of a fast quenching of the
persistent photoresponse, construction of the focal-plane array, new readout technique, and others. The advantages of
infrared photodetecting systems based on the group III-doped IV-VI in comparison with the modern photodetectors are
summarized. The spectra of the persistent photoresponse have not been measured so far because of the difficulties with
screening the background radiation. We report on the observation of strong persistent photoconductivity in
Pb0.75Sn0.25Te(In) under the action of monochromatic submillimeter radiation at wavelengths of 176 and 241 microns. The sample temperature was 4.2 K, the background radiation was completely screened out. The sample was initially in
the semiinsulating state providing dark resistance of more than 100 GOhm. The responsivity of the photodetector is by
several orders of magnitude higher than in the state of the art Ge(Ga). The red cut-off wavelength exceeds the upper
limit of 220 microns observed so far for the quantum photodetectors in the uniaxially stressed Ge(Ga). It is possible that
the photoconductivity spectrum of Pb1-xSnxTe(In)covers all the submillimeter wavelength range.
We have analyzed photoconductivity in PbSnTe(In) under the action of ~100 ns long terahertz laser pulses with the
wavelength 90 - 500 μm in the temperature range 4.2-300 K. Strong photoresponse has been observed at all wavelengths
used. Positive persistent photoconductivity is observed at T < 10 K, whereas negative non-persistent photoresponse
prevails at higher temperatures T ~ 25 K. Specific features of photoconductivity are discussed.
Photoelectric, transport and optical properties are studied for nanostructured PbTe(In) films. Synthesis of the films was
performed using evaporation of a target source to a glass substrate. The films have column-like structure with a mean
grain size varying from about 60 nm to 170 nm depending on the substrate temperature. Analysis of the data obtained
revealed that the conductivity of the films is determined by two mechanisms: charge transport along the inversion
channels at the grain surface and activation through barriers at the grain boundary. Persistent photoconductivity appears
in the films below T = 150 K. The frequency dependence of the relative photoresponse has a pronounced maximum. The
photoresponse in the ac mode may be by two orders of magnitude higher than in the dc measurements.
Doping of the lead telluride and related alloys with the group III impurities results in appearance of the unique physical
features of a material, such as persistent photoresponse, enhanced responsive quantum efficiency (up to 100
photoelectrons/incident photon), radiation hardness and many others. We present the physical principles of operation of
the photodetecting devices based on the group III-doped IV-VI including the possibilities of a fast quenching of the
persistent photoresponse, construction of the focal-plane array, new readout technique, and others. The advantages of
infrared photodetecting systems based on the group III-doped IV-VI in comparison with the modern photodetectors are
summarized. The spectra of the persistent photoresponse have not been measured so far because of the difficulties with
screening the background radiation. We report on the observation of strong persistent photoconductivity in
Pb0.75Sn0.25Te(In) under the action of monochromatic submillimeter radiation at wavelengths of 176 and 241 microns.
The sample temperature was 4.2 K, the background radiation was completely screened out. The sample was initially in
the semiinsulating state providing dark resistance of more than 100 GOhm. The responsivity of the photodetector is by
several orders of magnitude higher than in the state of the art Ge(Ga). The red cut-off wavelength exceeds the upper
limit of 220 microns observed so far for the quantum photodetectors in the uniaxially stressed Ge(Ga). It is possible that
the photoconductivity spectrum of Pb1-xSnxTe(In)covers all the submillimeter wavelength range.
Doping of the lead telluride and related alloys with the group III impurities results in appearance of unique physical features of a material, such as persistent photoresponse, enhanced responsive quantum efficiency (up to 100 photoelectrons/incident photon), radiation hardness and many others. As a result, single photodetectors based on Pb1-xSnxTe(In) demonstrate extremely high performance in the Terahertz wavelength range. Furthermore, it is shown that local long-lived non-equilibrium states are generated in Pb1-xSnxTe(In) alloys at low temperatures under the action of local Terahertz excitation. This result opens a possibility for construction of a "continuous" focal-plane array for detection of Terahertz radiation. Ideas for readout of information from this array are discussed.
Doping of the lead telluride and related alloys with the group III impurities results in appearance of the unique physical features of a material, such as persistent photoresponse, enhanced responsive quantum efficiency (up to 100 photoelectrons/incident photon), radiation hardness and many others. We present the physical principles of operation of the photodetecting devices based on the group III-doped IV-VI including the possibilities of a fast quenching of the persistent photoresponse, construction of the focal-plane array, new readout technique, and others. The advantages of infrared photodetecting systems based on the group III-doped IV-VI in comparison with the modern photodetectors are summarized. The spectra of the persistent photoresponse have not been measured so far because of the difficulties with screening the background radiation. We report on the observation of strong persistent photoconductivity in Pb0.75Sn0.25Te(In) under the action of monochromatic submillimeter radiation at wavelengths of 176 and 241 microns. The sample temperature was 4.2 K, the background radiation was completely screened out. The sample was initially in the semiinsulating state providing dark resistance of more than 100 GOhm. The responsivity of the photodetector is by several orders of magnitude higher than in the state of the art Ge(Ga). The red cut-off wavelength exceeds the upper limit of 220 microns observed so far for the quantum photodetectors in the uniaxially stressed Ge(Ga). It is possible that the photoconductivity spectrum of Pb1-xSnxTe(In)covers all the submillimeter wavelength range.
Persistent photoconductivity in a Pb0.75Sn0.25Te(In) alloy initiated by monochromatic submillimeter-range radiation at wavelengths of 176 and 241 μm was observed at helium temperatures. This photoconductivity is shown to be associated with optical excitation of metastable impurity states.
Doping of the lead telluride and related alloys with the group III impurities results in an appearance of the unique physical features of a material, such as persistent photoresponse, enhanced responsive quantum efficiency (up to 100 photoelectrons/incident photon), radiation hardness and many others. We review the physical principles of operation of the photodetecting devices based on the group III-doped IV-VI including the possibilities of a fast quenching of the persistent photoresponse, construction of the focal-plane array, new readout technique, and others. The advantages of infrared photodetecting systems based on the group III-doped IV-VI in comparison with the modern photodetectors are summarized. Some new ideas concerning the possibilities provided by the doped IV-VI are presented.
The possibilities and advantages of UV-laser ablation technique for deposition of doped PbTe thin films are discussed. To understand the effects of experimental parameters on layer formation the stages of laser sputtering of the target and film growth were investigated. Method of laser ionization RETOF mass spectrometry was used to obtain the energy distribution and chemical nature of evaporated particles as a function of wavelength and laser radiation power. The influence of experimental parameters on the deposited film thickness, stoichiometry and crystalline perfection was checked. The dependence of doped PbTe films photoelectrical properties on the experimental parameters.
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