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Lighting
Published in Sue Reed, Dino Pisaniello, Geza Benke, Kerrie Burton, Principles of Occupational Health & Hygiene, 2020
Photosensitivity is an abnormally high reactivity in the skin or eyes to UV radiation or natural sunlight. It may be induced by ingestion, inhalation or skin contact with certain substances known as photosensitisers. Symptoms will vary with the amount of UV radiation, type and amount of photosensitiser, skin type, and age and sex of the person exposed. Photosensitisation of the skin and eyes can be caused by exposure to specific industrial chemicals. The skin can be affected by dermal exposure or inhalation. The eyes can be affected by volatile fumes.
Lighting
Published in Sue Reed, Dino Pisaniello, Geza Benke, Principles of Occupational Health & Hygiene, 2020
Photosensitivity is an abnormally high reactivity in the skin or eyes to UV radiation or natural sunlight. It may be induced by ingestion, inhalation or skin contact with certain substances known as photosensitisers. Symptoms will vary with the amount of UV radiation, the type and amount of photosensitiser, skin type, and the age and sex of the person exposed. Photosensitisation of the skin and eyes can be caused by exposure to specific industrial chemicals. The skin can be affected by dermal exposure, and volatile fumes can affect inhalation and the eyes.
Nonionizing Radiation
Published in Martin B., S.Z., of Industrial Hygiene, 2018
Photosensitivity involves an abnormal skin reaction to UV in the presence of a chemical substance. Although a variety of chemical substances may be involved in photosensitive reactions, medications are prominent. Hence, photosensitivity may be more prevalent in elderly workers because they use medications more frequently. Two types of photosensitivity occur: phototoxicity and photoallergy. Phototoxicity, which is more common, is analogous to contact dermatitis. In general, it manifests as a sunbum-type response on sunlight-exposed parts of the body: face, arms, and hands. Photoallergy is an acquired response involving the immune system. The body’s response may include unusual reactions such as urticarial or eczematous lesions. Photoallergens include some salicylanilides and antibiotics, hexachlorophene, cosmetics, and colognes containing musk ambrette.
Evolution of the Cu2ZnSnS4 phase based on the sulfurization-crystallisation duration of the CuS/SnS/ZnS stack formed by thermal evaporation
Published in Journal of Asian Ceramic Societies, 2023
N. Cruz Santiago, E. Ramirez Morales, T. González Sánchez, R. Castillo Palomera, L. Rojas Blanco, G. Hernández Galvez, E. Miranda Mandujano, C. Ricárdez Jiménez, A. Trujillo Narcía, Omar Sarracino Martínez
The photosensitivity was calculated using the expression , where and are the conductivity in light and dark respectively, and Pinc is the incident power [49]. The conductivity of the films increased with increasing annealing time (Table 3). The calculated photosensitivity for the films with 5 min and 20 min annealing time was 0.160 cm/ΩW and 0.152 cm/ΩW respectively. In the literature, the reported values of photosensitivity are in the range of 0.14–0.8 cm/ΩW (Table 3 and the references therein). The film with the shorter annealing time shows higher photosensitivity, which can be attributed to the larger crystallite size and phase-purity of the CZTS material as discussed in the XRD and Raman analysis. Further, the SEM and AFM images reveal larger grains for the short-duration annealed film, implying less grain boundaries, which reduces the recombination of photo-generated charge carriers [50]. On the other hand, the lower photosensitivity of the film subjected to larger annealing duration can be a result of the phase segregation and possible increase in recombination centers [51]. The dark and light conductivity, and photosensitivity of the films are shown in Table 3.
Temperature dependent electrical and optical properties with higher photosensitivity of Cu2Se absorber thin films for photo voltaic application
Published in Inorganic and Nano-Metal Chemistry, 2021
J. Henry, T. Daniel, V. Balasubramanian, K. Mohanraj, G. Sivakumar
The photosensitivity can be calculated using the formula, where S is photosensitivity, Idark is dark current and Ilight is current generated under illumination. The obtained photosensitivity values are listed in Table 4. The photosensitivity increases with increasing annealing temperature except at 300 °C due to the increase in crystallite size of the Cu2Se films. Besides, the decrease in optical band gap and increase in conductivity of the film with annealing temperature may cause the increase in photosensitivity of the films. It means a higher quantity of photo-generated carrier. The present result identified the Cu2Se as a potential active layer for thin film solar cell application.
Thermally evaporated CZTSe thin films for solar cell application: Study on the effect of annealing time
Published in Particulate Science and Technology, 2020
J. Henry, K. Mohanraj, G. Sivakumar
The photo I-V plot of CZTSe thin films annealed at 300°C for 2 h, 4 h and 6 h are shown in Figure 10. The plot recorded under visible light shows higher photo current than that of the dark condition. This is due to the production of electron hole pairs under irradiation, the light excites electrons in the valance band to the conduction band and then holes in the CZTSe thin film increase. The photosensitivity of the film can be calculated according to the formula (Sadekar, Ghule, and Sharma 2015)where S is photosensitivity, Idark is dark current and Ilight is current generated under illumination. The photosensitivity is found to be 70, 73, and 140% for the films annealed at 300°C for 2, 4, and 6 h, respectively. The enhancement of photosensitivity is attributed to the improvement of crystalline properties with increasing in annealing time which leading to the reduction of the structural like strain etc (Ibraheam et al. 2017). CZTSe is known to be typically p-type. Light irradiation excites electrons in the valence band to the conduction band and then increases the holes in them. As a result, the current is increased obviously and the conductivity of the film is enhanced. This obvious photoresponsive behavior indicates the potential use CZTSe thin films in solar energy conversion systems, such as the fabrication of photovoltaic devices (Shi et al. 2013). The obtained photocurrent value is compared with earlier reports and are presented in Table 2. By comparing our results (Table 2) with earlier reports, it can be inferred that the present study shows high values for photocurrent