A multifunctional optical-thermal logic gate sensor array based on ferroelectric BiFeO_(3) thin films

The growing need to process a diverse range of data has ignited effort in developing new multifunctional logic gate devices.In this article,we report a new form of all-in-one logic gate system that exploits the photoresponsivity of a self-powered multifunctional BiFeO_(3)(BFO)sensor material.The BFO sensor can not only detect both light intensity and temperature,but it can also execute three common logic gates of“AND”,“OR”,and“NOT”by converting optical and thermal inputs into electrical output.The diverse functionality of the BFO logic gate sensor array utilizes the unique light-and temperaturecontrolled energy band structure and carrier behavior of the BFO material.To demonstrate the potential,a 3×3 logic gate sensor matrix is developed,which successfully detected light and temperature distributions,and accurately produced the three basic logic gate operations.This work provides a new route to construct highly integrated multifunctional electronic devices for the advancement of large sensing,communication,and computing operations.

Development of optical-thermal coupled model for phosphor-converted LEDs

In this review, first, we discussed the effect of phosphor features on optical properties by the software simulation in detail. A combination of these parameters: phosphor material, phosphor particle size and particle distribution, phosphor layer concentration, phosphor layer thickness, geometry, and location of the phosphor layer, will result in the final optical performance of the phosphor layer. Secondly, we introduced how to improve light extraction efficiency with various proposed methods. Thirdly, we summarized the thermal models to predict the phosphor temperature and the junction temperature. To stabilize the optical performance of phosphor-converted light emitting diodes (PC-LEDs), much effort has been made to reduce the junction temperature of the LED chips. The phosphor temperature, a critical reliability concern for PC-LEDs, should be attracted academic interest. Finally, we summed up optical-thermal coupled model for phosphors and summarized future optical- thermal issues exploring the light quality for LEDs. We foresee that optical-thermal coupled model for PC-LEDs should be paid more attention in the future.

On the Development of a Simple and Portable Ground-Based Infrared Imaging System for Lunar and Atmospheric Studies

A small, portable, infrared (wavelength of 7 - 14 μm) system has been designed and developed to study the thermal behavior of the lunar surface and for thermal remote sensing applications. The principal operation of the system depends on collecting large amounts of infrared light, using a modified Newtonian telescope. The light from the object is reflected by the primary mirror and the secondary mirror. This collected light is then focused into a thermal camera by using an intermediate germanium lens as a field lens to provide a real optical image on the camera sensor. Several observations have been obtained out using the developed system, and eliciting some interesting results. These include lunar observations during different phases and during partial lunar eclipse. The thermal behavior of the lunar surface was identified, proving the system’s functionality and performance. The developed system is, also, particularly suitable tool for outreach programs and students projects which can possibly offer useful learning and exploration opportunities for students in different applications. In this paper, a brief description about the developed system is provided. Some of the obtained results are illustrated. The future applications and improvements to the designed system are also summarized.