In this paper, versatile Metal/TCO/p-Si Schottky Barrier Diodes (SBDs) with dissimilar TCO intermediate layers (ZnO and ITO) were fabricated by RF magnetron sputtering technique. An overall electrical performance comparison between the Al/ZnO/p-Si, Au/ITO/p-Si and the conventional Au/p-Si structures is carried out. The measured I-V characteristics indicate that the proposed Al/ZnO/p-Si design exhibits an outstanding capability for achieving a high rectifying ratio of 142 dB. This is mainly due to the enhanced Schottky barrier height (SBH) of 0.75 V and close to unite ideality factor (n = 1.23). Such behavior can be attributed to the enhanced interface quality achieved by introducing TCO inter-layers, which could decrease the Series resistance. A comparative study of the elaborated structures performance is carried out in which new Figures of Merit (FoM) parameters that combine both electrical and thermal stability performances are proposed. The Experimental results show that the proposed designs with ITO and ZnO sub-layers exhibits improved FoM parameters as compared to the conventional Au/p-Si structure. Moreover, this comparative study enables to the designer to acquire a comprehensive review about the Si-based SBDs design tradeoffs. It is demonstrated that the insertion of a TCO inter-layer might be beneficial for avoiding the degradation related-heating effects. Therefore, the proposed designs offer the possibility of bridging the gap between superior electrical performance and high thermal stability, which makes them suitable for developing high-performance Schottky solar cells and sensing applications.

Recently, mobile crowd sensing (MCS) is captivating growing attention because of their suitability for enormous range of new types of context-aware applications and services. This is attributed to the fact that modern smartphones are equipped with unprecedented sensing, computing, and communication capabilities that allow them to perform more complex tasks besides their inherent calling features. Despite a number of merits, MCS confronts new challenges due to network dynamics, the huge volume of data, sensing task coordination, and the user privacy problems. In this paper, a comprehensive review of MCS is presented. First, we highlight the distinguishing features and potential advantages of MCS compared to conventional sensor networks. Then, a taxonomy of MCS is devised based on sensing scale, level of user involvement and responsiveness, sampling rate, and underlying network infrastructure. Afterward, we categorize and classify prominent applications of MCS in environmental, infrastructure, social, and behavioral domains. The core architecture of MCS is also described. Finally, we describe the potential advantages, determine and reiterate the open research challenges of MCS and illustrate possible solutions.

Actually, wireless sensor networks represent a substantial part in IoT. However, their limitation requires a special consideration in IoT applications. For their integration with the internet, it is necessary to adapt such networks using different middleware, with taking into account various challenges such as heterogeneity and interoperability. Previously Service Oriented Architecture (SOA) was the suitable design, but with a better practice, a new design called microservice becomes the leader due to its high performance and its suitability for IoT applications. In this paper, we first survey the most important middleware that have been proposed to handle WSN through IoT. Also, we discuss the most crucial microservices that handle different integration factors by making them supported by the proposed middleware. Our proposal is inspired from artificial neural network architecture to allow dynamic service interaction; it supports unlimited services with a regard to various device capabilities separately of the cloud technologies. Moreover, the evaluation of our design clearly shows that our middleware allows a lightweight WSN integration with IoT regarding to their limitations and requirements.