Expeditious development of PENGs has been restricted several problems such as toxicity, high cost, and long-life. Herein, we report a biowaste crab shell-extracted chitin nanofiber (CNF) and CNF/poly(vinylidene fluoride) (PVDF)-based biocompatible, biodegradable, low cost, light weight, flexible, highly durable and efficient piezoelectric nanogenerators (PENGs) that enable harvesting of electrical energy from the mechanical energy of a living system. The pure CNF thin film-based piezoelectric nanogenerator (CPENG) shows excellent output performances (open circuit output voltage (V_oc) = 22 V, short circuit current (I_sc) = 0.12 μA) with a high piezoelectric coefficient, d₃₃ = 9.49 pC N⁻¹. The PENG based on CNF/PVDF (PCPEG) also shows very good output characteristics (V_oc = 49 V and I_sc = 1.9 μA). The incorporation of CNF in a PVDF matrix noticeably enhanced the electroactive β-phase nucleation, (F(β)) ∼ 81%, with a superior d₃₃ ∼ 35.56 pC N⁻¹. The PCPENG is able to charge a 2.2 μF capacitor to 3.6 V within a short time span (20 seconds) and illuminate 22 blue LEDs connected in series. Our as-fabricated PENGs could be suitable for long-life in vivo biomedical energy harvesting devices that can harvest energy from blood flow and heart beats and charge energy storage devices from mechanical energy such as body movements, moving cars, sea waves, air flow, and rain drops.

In this report the synthesis of novel zinc oxide (ZnO) with a lower defect density and its effect on the Al/ZnO Schottky junction has been demonstrated. The defect density was estimated by positron annihilation lifetime measurement which ensures the material's superiority (i.e. free from point defects or any type of vacancies) over the earlier reported results. The thin film device of synthesized ZnO was fabricated on an ITO coated glass substrate. As the front contact was made by aluminium, the characteristic I–V produced rectifying Schottky behavior. The underlying charge transport mechanism through a metal–semiconductor (i.e. Al/ZnO) junction was analyzed on the basis of thermoionic emission theory to find out the quality of the fabricated device. In this regard we have studied the charge transport mechanism by measuring the density of states (DOS) at the Fermi level, mobility-lifetime product and diffusion length.

A novel thiocyanate bridged 2D MOF, [CdL(μ-1,3-SCN)₂]_n, [HL = 2-(2-(ethylamino)ethyliminomethyl)-6-ethoxyphenol] has been synthesized and characterized by X-ray crystallography. The band gap of the synthesized material in the solid state has been determined by experimental measurements and compared with the theoretical value obtained from DFT calculations. For the first time, the single crystal X-ray crystallography of a MOF has been reported along with its applicability in photosensitive devices.