NUSOD Blog

Connecting Theory and Practice in Optoelectronics

Category Archives: sensor

Call for Papers: Special Journal Issue on Multiscale Modeling of Solar Cells

In the last two decades, there has been an increasing interest in multiscale modeling applied to electronic devices. Several factors are driving this trend. On the one hand, device dimensions of “classical” devices like MOSFETs have continuously been scaled down in order to increase device performance. On the other hand, specific properties of quantum structures are systematically utilized in modern devices. The embedding of the active device region in its environment including access regions and contacts, and the mutual interaction between different aspects like optics, thermal heating, strain and carrier transport requires an involved multiscale/multiphysics simulation approach which can handle different physical models and different length or time scales.

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NUSOD 2016 Preview: Modeling of light soaking effect in CdTe Solar Cells

light soakNearly all photovoltaic technologies exhibit changes in device performance under extended illumination, or “light soaking”. Experiments on both commercial modules and research cells based on CdTe technology have shown improvement of cell performance under light soaking conditions for up to 20 hours. Many accredited such phenomena to the passivation of traps and migration of Cu ions. In this work, we employed a self-consistent one-dimensional (1D) diffusion-reaction simulator to study the migration and passivation of Cu related dopants in CdTe solar cell as a function of soaking conditions. Read more of this post

Surface plasmon-enhanced photodetection in MoS2 phototransistors

weida+blog2Graphene and related 2-dimensional (2D) materials have emerged as potential building blocks for a variety of fundamental optical and electronic components, including field-effect transistors, nonvolatile memory devices, photonics devices, and phototransistors. Recently, molybdenum disulfide (MoS2) materializes as an alternative 2D nanoflake, due to its optical sensitivity, mechanical flexibility, extraordinary on/off ratio, absence of dangling bonds and compatibility to silicon CMOS processes, which may overcome the drawbacks of graphene. However, the performance of previously reported MoS2 phototransistors is limited by the low photoresponsivity which is largely due to its poor light absorption properties. Read more of this post

How to simulate the photogating effect in InAs nanowire phototransistors?

phototransistorSemiconductor nanowires promise light detection with enhanced sensitivity and faster transport speed. However, the short photocarrier lifetime, small light-sensing area, and weak optical absorption of nanowires cause serious problems. A possible solution lies in the photogating effect of semiconductor nanostructures, which was recently utilized in graphene-based phototransistors. Photocarriers located near the conductive channel form a strong local electric field to regulate the channel conductance through capacitive coupling. Read more of this post