Hydrogen in semiconductors

Abstract

Hydrogen in crystalline semiconductors has become a recent curiosity because of its high diffusivity and strong chemical activity in such materials. In contrast to the proton motion in ionic materials which gives rise to an enhanced conductivity, hydrogen in electronic materials interact with structural disorders and chemical impurities to control the electronic flow. Deep gap states in crystalline semiconductors due to various disorders such as surface/interface, grain boundaries, dislocations, irradiation and implantation damage etc. have been removed due to hydrogen bondings. Hydrogen incorporation is done by plasma and direct ion beam hydrogenation methods, implantation technique and by a novel technique of damage free introduction. The most studied materials are silicon and gallium arsenide. I-V, C-V, DLTS and IR studies have been carried out on hydrogenated semiconductors to characterize the electronic flow, gap states and the nature of chemical bonds. Improvement in ideality factors of diodes, reduction in free carrier concentration, removal or reduction of deep states and appearance of new bondings such as Si-H, P-H, B-H etc. have been observed from various techniques. The present paper reviews the various features of hydrogenation studies in crystalline silicon and gallium arsenide and highlights our results of hydrogenation studies on Pd/semiconductor devices.

Induced conductivity in sol-gel ZnO films by passivation or elimination of Zn vacancies

“…Hydrogen passivation of defects has been recognized to be the major factor in the successful development of complementary metal-oxide-semiconductor devices. [18][19][20] Recent works by one of the authors have also demonstrated that hydrogen passivate cation vacancies in yttrium aluminum oxide Y 3 Al 5 O 12 and dramatically modified its optical and electronic properties. 21,22 The current work shows that hydrogen passivates Zn vacancy related defects and plays an important role in tuning the electrical properties of ZnO films as well.…”

Color - Tunable Phosphors in Weberite Type System, La3 SbO7 :Bi3+ , Eu3+ for Near-UV LED Applications

“…Charge transfer bands which have high energy than C band are coined as D band. [13][14][15][16][17] Emission properties of Bi 3 + ions vary with host lattice. Rambabu et al [18] have reported the greenish-yellow luminescence of Bi 3 + ions in lanthanide vanadate phosphors.…”

Observation of Conductivity Type Change in Swift Heavy Ion Irradiated Metal/Semiconductor Devices

“…Due to its single vacancy (H+ & H-), hydrogen has ability to passivate the electrically active dangling bonds in crystalline silicon semiconductor [6][7][8][9]. For the p-type silicon, hydrogen gas has a positive charge state [10].…”

“…A dipole layer is formed at the interface which changes the work function differences between the metal and semiconductor. The diffused hydrogen in the semiconductor causes the defect deactivation phenomenon [9]. The irradiated and hydrogenated devices subsequently annealed with an aim to modify the radiation induced defects.…”