Anodic electrode reaction of p-type silicon in 1-ethyl-3-methylimidazolium fluorohydrogenate room-temperature ionic liquid

The anodic electrode behavior for a p-type silicon single crystal electrode ((10 0), p = 0.01-0.02 Q cm, boron doped) was examined in the 1-ethyl-3-methyl imidazolium fluorohydrogenate, EtMeIm(FH)(2.3)F, room-temperature ionic liquid (RTIL). The electrochemical behavior was very similar to that in conventional HF aqueous solution. After the anodic electrode reaction, the Si electrode was uniformly covered with a mesoporous Si layer having a pore size of similar to 25 nm. The mesoporous layer did not exhibit a photoluminescence spectrum in the visible region due to the lack of Si-H termination. However, after chemical treatment with an ethanolic HF solution, a subset of the porous Si samples showed a very weak photoluminescence. (c) 2007 Elsevier Ltd. All rights reserved.