Gallium Arsenide and Gallium Nitride Semiconductors for Power and Optoelectronics Devices Applications

Abstract

The advancement in technology in semiconductor materials significantly contributed in improvement of human life by bringing breakthrough in fabrication of optoelectronics and power devices which have wide applications in medicine and communication. The Gallium Arsenide (GaAs) and Gallium Nitride (GaN) are versatile materials for such applications but with relative merits and demerits. GaAs transistors are suitable for both narrowband and wideband applications due to very wide operating frequency range (30 MHz to millimetre-wave frequencies as high as 250 GHz). They are highly sensitive, generate very little internal noise and have power density typically around 1.5 W/mm. But low break down voltage (5x105V/cm), low output power (5-10W) and inability to withstand higher temperatures are the main limitations. On the other hand, GaN possess the improved physical and chemical characteristics, with high output power, high operating temperature (1000°C in vacuum), fast heat dissipation, high breakdown voltage (4x106V/cm), high power density (5-12W/mm), high frequency characteristics and large band gap (3.4eV) which allow significant reduction of devise size. Also high breakdown voltage increases the overall impedance which make it suitable in matching process and enables efficient operation in broad band region. The present paper critically analyses the GaAs and GaN semiconductors in relation to their significant physical and chemical properties, which make them suitable to make efficient power and optoelectronics devices for applications in communication, space and medicine.

Molecular design, synthesis, properties, and applications of organic triplet emitters exhibiting blue, green, red and white room-temperature phosphorescence

“…13 The major problem with blue RTP materials is that phosphorescence is usually red-shifted in comparison to fluorescence because the triplet-excited states usually have lower energy compared to the S 1 excited state, following the molecular analog of the Hund rule. 6 The S 1 -T 1 energy gap of the c ic u excitation is determined by the 2(iu|iu) expression, being twice the exchange integral between the HOMO and LUMO, eqn (1). In order to achieve blue RTP, the organic compounds have to possess triplet excitation energy levels of ca.…”

“…However, the most effective semiconductive materials up-to-date are inorganic, mainly consisting of silicon, germanium and binary compounds such as gallium arsenide. 1 The fabrication of semiconductors involves the usage of hazardous substances, e.g., phosphorus, antimony, and arsenic. 2 This poses a bunch of challenges for researchers such as achieving high device performance by replacing the inorganic constituents of LEDs with organic ones, while minimizing environmental risks.…”

“…However, the most effective semiconductive materials up-to-date are inorganic, mainly consisting of silicon, germanium and binary compounds such as gallium arsenide. 1 The fabrication of semiconductors involves the usage of hazardous substances, e.g. , phosphorus, antimony, and arsenic.…”

Туннелирование через барьеры Шоттки Ni/n-GaN по локализованным состояниям дефектов

“…Благодаря высокой величине напряжения пробоя и дрейфовой скорости в GaN, полевые транзисторы с барьерами Шоттки на GaN по ряду параметров существенно превосходят кремниевые аналоги. Однако развитие силовых диодов Шоттки на GaN натолкнулось на значительные трудности, во многом связанные с необходимостью одновременно обеспечить высокую плотность максимального прямого тока, низкую плотность обратного тока утечки и высокое напряжение электрического пробоя [1][2][3]. Требуются дальнейшие исследования, чтобы полностью реализовать преимущества фундаментальных свойств GaN [1][2][3].…”

Realizing Ultrafast Response Speed for Self-Powered Photodetectors with a Molecular-Doped Lateral InSe Homojunction

“…Superior photodetectors play a pivotal role in modern technology, spanning fields such as communication, information technology, and optoelectronics. − However, contemporary semiconductor photodetectors face a myriad of challenges in terms of high-speed response, sensitivity, and material selection, necessitating novel materials and structures to enhance device performance and meet the demands of future applications. , …”