Sensitization of photoconductivity in tetragonal lead monoxide
TL;DR: In this paper, the thermal sensitization process for the enhancement of photoconductivity in tetragonal lead monoxide has been investigated, and at a critical annealing temperature the photosensitivity has a maximum value (≅5×102) while the conductivity is observed to have a minimum value (approximately 10−10 cm).
Abstract: The thermal sensitization process for the enhancement of photoconductivity in tetragonal lead monoxide has been investigated. At a critical annealing temperature the photosensitivity has been found to have a maximum value (≅5×102) while the conductivity is observed to have a minimum value (≅10−10Ω cm). The transient response of the photocurrent exhibits an overshoot, the height of which is strongly dependent on the annealing temperature. These and other findings have been explained on the basis of sensitization due to the creation of two types of centres in the material.
Citations
More filters
TL;DR: In this paper, the structural and optical properties of thin lead oxide films were studied using x-ray diffraction measurements, which revealed that the film structure is governed by both energetics and kinetics.
Abstract: The structural and optical properties of thin lead oxide films were studied. Thin films were prepared by reactive dc magnetron sputtering of lead (Pb) targets in an Ar/O2 mixture. The structure has been determined by x-ray diffraction measurements, which show that crystalline lead oxide films of different composition (PbO, PbO1.44, Pb2O3, and PbO2) have been formed upon increasing oxygen flow (partial pressure). This result is confirmed by Raman spectroscopy. The effect of postdeposition annealing on the structural properties of PbO films reveals that the film structure is governed by both energetics and kinetics. X-ray reflectivity measurements were used to determine the thickness, density, and roughness of the films. The calculated film density values are almost equal to the bulk density of the material, showing that compact, nearly void free films are formed. The optical properties of the films have been studied from the reflectance and transmittance spectra recorded by optical spectroscopy measurement...
58 citations
TL;DR: In this paper, the synthesis and morphology control of emerging layered black phosphorus analogues (BPAs) is discussed, and the latest progress in understanding the fundamental properties of BPA nanostructures and the recent advances in constructing prototypical high-performance BPA-based devices for practical applications.
Abstract: In recent years, layered black phosphorus (BP) nanostructures have demonstrated great potential applications in transistors, optoelectronics and logic devices due to their excellent intrinsic electronic and optoelectronic properties. However, the high cost of BP and its rapid degradation upon exposure to ambient conditions turn out to be the two critical bottlenecks hampering practical applications. With the development of semiconductors in leaps and bounds, a new wave of exploration of black phosphorus analogues (BPAs), whose excellent optoelectronic performance and high chemical stability under ambient conditions unveil great promise for practical applications, has emerged. This review presents the synthesis and morphology control of emerging BPAs, the latest progress in understanding the fundamental properties of BPA nanostructures, and the recent advances in constructing prototypical high-performance BPA-based devices for practical applications. Finally, the prospects for future research, application opportunities, and the accompanying challenges of BPAs are discussed.
42 citations
TL;DR: In this paper, the optical properties of α-PbO2 phase were calculated from absolute values of transmittance and reflectance at nearly normal incidence of light by spectrophotometer measurements.
41 citations
TL;DR: In this article, the effect of substrate temperature on the growth mechanism and physical properties of polycrystalline lead oxide films was investigated and the band gap value was found to be in the range of 2.3 to 2.62 eV.
Abstract: Thin films of lead oxide were synthesized by cost effective spray pyrolysis technique at different substrate temperatures on glass substrates. Effect of substrate temperature on the growth mechanism and physical properties of the films was investigated. All the films were polycrystalline in nature with tetragonal structure corresponding to α-PbO. The films coated at 225 °C and 275 °C were (1 0 1) oriented, while the films deposited at 325 °C and 375 °C were (0 0 2) oriented. Above 375 °C, the pure tetragonal nature deteriorated and the peaks corresponding to orthorhombic phase were observed. The band gap value was found to be in the range of 2.3 to 2.62 eV. All the films had a resistivity of the order of 103 ohm-cm. A minimum resistivity of 0.0191 × 103 ohm-cm was obtained for the film coated at 325 °C. The activation energy increased with increase in substrate temperature.
32 citations
TL;DR: In this paper, the authors reported high-performance inverted polymer solar cells with lead monoxide (PbO)-modified indium tin oxide (ITO) as the cathodes.
31 citations
References
More filters
Book•
01 Jan 1978
1,693 citations
"Sensitization of photoconductivity ..." refers background or result in this paper
...Such oxygen impurity sensitization is known in many photoconducting materials [ 9 ] and it is also quite likely to be present in PbO....
[...]
...The photoconducting properties of lead monoxide (PbO) have recently drawn considerable attention since finding a number of applications in imaging devices such as television pick-up tubes (Plumbicon) [1, 2], electrophotography [ 3 ] and electroradiography [4]....
[...]
...This behaviour of I L with temperature is exactly the reverse of that observed for orthorhombic PbO [ 3 ]....
[...]
Book•
01 Jan 1963
1,194 citations
"Sensitization of photoconductivity ..." refers background in this paper
...The various features described above may be explained on the basis of sensitization of photoconductivity by impurity or defect centres [ 11 ]....
[...]
TL;DR: In this article, single-crystal platelets (3×3×0.1 mm) of both tetragonal and orthorhombic lead oxide have been grown from dilute NaOH solutions at high pressures using conventional hydrothermal techniques.
Abstract: Single‐crystal platelets (3×3×0.1 mm) of both tetragonal and orthorhombic lead oxide have been grown from dilute NaOH solutions at high pressures using conventional hydrothermal techniques. The predominant yield of the two phases was varied in accord with the P‐T phase diagram of PbO. Electrical measurements include the Hall coefficient and electrical conductivity as a function of temperature, while the corresponding photoeffects and optical absorption with monochromatic radiation were also studied. ``As‐grown'' tetragonal crystals were highly conducting n‐type with σ(300°K) ∼10−3 to 1.0Ω−1 cm−1, and had Hall mobilities of about 100 cm2V−1 sec−1. In constrast the ``as‐grown'' orthorhombic crystals were rather insulating with σ(300°K) ∼10−5Ω−1 cm−1 and a Hall mobility μe∼50 cm2V−1 sec−1. Heat treatment in air altered both the electrical and optical properties. Photoconductivity was observed in both crystalline forms. The optical measurements indicate band transitions at 1.90 eV and 2.75 eV for the tetragon...
67 citations
TL;DR: In this paper, a method was described for preparing very pure PbO from lead acetate with ammonia at room temperature, using polyethylene vessels to prevent spontaneous recrystallisation in water from yellow orthorhombic to red tetragonal PbOs.
18 citations
TL;DR: In this paper, an electrophotographic multilayer system with adielectric foil which is directly glued to the binder layer without any additional adhesive penetrating into the layer, is used.
Abstract: An advantage of electrophotographic multilayer systems is that both for the generation and for the storage of pictorial electric charges. layers can be used with optimum properties for each function. Large-area and highly sensitive PbO binder layers which are marked by an excellent absorption of X-rays. and with adielectric foil which is directly glued to the binder layer without any additional adhesive penetrating into the layer, are used. Since the time taken to irradiate the whole picture area has to be short, a liquid electrode is used to increase the sensitivity. Essential steps in the performance of this process are shorting ofthe electrodes after taking the picture and subsequently the fast removal of the liquid electrode. All conditions are described with the aid of examples.
13 citations