Atmospheric pressure chemical vapour deposition of SnSe and SnSe2 thin films on glass

Novel semiconductor materials for the development of chemical sensors and biosensors: a review.

Currently, selenium (Se)-based compound semiconductors (CISe, CIGSe and CZTSe) are considered as the active materials in the photovoltaic world. However, these materials exhibit couple of issues related to stoichiometry maintenance and scarcity of their constituent elements (In, Ga), which limit their massive production for future energy demands. These issues could be rectified by introducing a non-toxic, inexpensive and earth-abundant binary material. One such material is a tin monoselenide (SnSe), which exhibits a high chemical stability along with attractive physical properties namely, suitable band gap (1.3 eV), high absorption coefficient (105 cm−1) and p-type conductivity. These properties indicate SnSe as a competitive substitute in place of conventional absorbers in thin film solar cells. Despite of its remarkable properties, only a few reports were published on the fabrication of SnSe-based solar cells with poor efficiency (≤1 %). This indicates a need to review on the physical properties of SnSe and its device structures in a deeper sense. In this context, the present review describes the different methods of preparation of SnSe films and their physical properties along with the details of photovoltaic device fabrication. We highlighted the different factors that are limiting the efficiency of SnSe solar cells, and a few suggestions were included to overcome these problems for further improvement of these cells. This review will enrich and stimulate the readers to further investigate the growth of SnSe thin films and their devices, for the development of >20 % efficient SnSe solar cells.

Perspectives on SnSe-based thin film solar cells: a comprehensive review

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Field effect transistors (FETs) are electrochemical transducers upon which micro-sized solid-state chemical sensors and biosensors, the so-called Bio-chem-FETs, can be developed. The chapter first discusses the key issues of FET operation. It then describes the ways of introducing chemical and biochemical sensitivity and selectivity to analytes, using either chemically activ sensing elements or biological recognition elements. The new advances in Bio-chem-FET design, based on novel carbon and inorganic nanomaterials, are then presented. Finally, the current analytical limitations are presented, followed by a discussion on the future trends and possible improvement strategies of the Bio-chem-FETs in relation to low detection limits, high sensitivity, in-vivo applications and long operational lifetimes.

7 – Bio-chem-FETs: field effect transistors for biological sensing

The effect of adsorption and temperature (300-450 K) on the electrical resistivity of SnSe thin films on the thickness range 500-2500 AA was investigated. Adsorption of oxygen has considerable influence on the electrical resistivity and it is observed to act as a p-type dopant. The temperature variation of resistance indicates interesting irreversible behaviour in the first heating cycle and the behaviour is suspected to be due to acceptor formation at higher temperatures. Adsorption and annealing were found to have a significant effect on the temperature variation of the resistance of SnSe thin films.

https://iopscience.iop.org/article/10.1088/0268-1242/2/8/008/pdf

N Ganesan

Papers

The influence of gas adsorption and temperature on the electrical resistivity of SnSe thin films