Stability & durability of self-driven photo-detective parameters based on Sn1-ß Sb ß Se (ß = 0, 0.05, 0.10, 0.15, 0.20) ternary alloy single crystals.

In the present investigation Sn1-ß Sb ß Se crystals are grown using the direct vapor transport method. The crystals after growth were analyzed by EDAX and XPS to confirm the elemental composition. The surface morphological properties were studied by scanning electron microscope, confirming a flat surface and layered growth of the Sn1-ß Sb ß Se crystals. The structural properties studied by X-ray diffraction and high-resolution transmission electron microscopy confirm the orthorhombic structure of the grown Sn1-ß Sb ß Se crystals. The Raman spectroscopic measurements evince the presence of B2g and Ag vibration modes. The PL intensity peak at ∼400 nm to 500 nm confirms the energy band gap. The indirect energy band gap of 1.18 eV was evaluated using Tauc plot by employing UV-visible spectroscopy making it a promising candidate for optoelectronic and photonic applications. The pulse photo response of pure and doped samples was studied under a monochromatic source of wavelength 670 nm and intensity of 30 mW cm-2 at zero biasing voltage firstly on day one and then the same samples were preserved for 50 days and the stability of the photodetectors was observed. Photodetector parameters such as rise time, decay time, photocurrent, responsivity, sensitivity, and detectivity were observed, and evaluated results are presented in this article.

Flexible paper based piezo-resistive sensor functionalised by 2D-WSe2 nanosheets.

High-performance electronics demand extremely sensitive piezo-resistive sensors with important features such as low-fabrication cost, easy implementation, low power consumption and high-pressure sensitivity over broad pressure range. Herein, we report a flexible piezo-resistive paper-based device functionalised by WSe2 nanosheets. An efficient and low-cost fabrication strategy using Whatman filter paper and tissue paper is adopted for versatile sensing applications. The WSe2 nanosheets were synthesized by high-yield and size-controlled liquid phase exfoliation technique. The flexible WSe2 nanosheets-paper sensor shows excellent response in broad pressure range of 1 Pa-100 kPa with exceptionally high sensitivity of 29.24 kPa-1, current responsivity of 70 and response time of 100 ms. The pressure sensor is also employed to recognize the pressure generated due to finger tapping. Encouragingly, the piezo-resistive sensors can also sense extremely small pressure differences of about 1.4 Pa generated by water drops.

Mammary hamartomas--a report of 15 cases.

The mammary hamartoma is a poorly recognised benign breast neoplasm. For diagnosis one usually correlates the clinical, mammographic, gross and histologic features. This study of fifteen cases emphasises the histomorphologic criteria for diagnosis especially in the absence of mammographic picture, viz. a clinically palpable, well encapsulated mass which on histology shows normal breast epithelium admixed with fat, fibrous tissue and other mesenchymal elements. The epithelium in the hamartomas studied showed changes seen in normal breast especially in the progestational phase of the menstrual cycle. The stroma was either densely collagenous, hyalinised or cellular and admixed with fat in various proportion in thirteen cases, muscle in two cases and thick muscular arteries in four cases. It also showed pseudoangiomatous hyperplasia in seven cases. The importance of this change and probable evolution is discussed therein.