Portal de Periódicos da CAPES

Photoluminescence and surface photovoltage of ethynyl derivative‐terminated Si(111) surfaces

2009; Wiley; Volume: 7; Issue: 2 Linguagem: Inglês

10.1002/pssc.200982474

1862-6351

Florent Yang, Ralf Hunger, Klaus Rademann, Jörg Rappich,

Semiconductor materials and interfaces

Abstract The electrochemical grafting of ethynyl derivatives on Si(111) surfaces has been investigated by means of pulsed photoluminescence (PL) and surface photovoltage (SPV) techniques. Ethynyl derivatives (ethynyl‐MgCl, ethynyl‐MgBr, propynyl‐MgBr, and phenylethynyl‐MgBr) from Grignard compounds were used. By SPV, a high surface photovoltage signal, U Ph , is observed. The halogene in the Grignard reagents influences strongly the electronic properties and the polymerisation process, i.e. Br in the Grignard compound leads to better electronic properties than Cl. The propynyl‐terminated Si surface shows the highest PL intensity and at the same time the weakest U Ph signal, i.e. this polymeric layer induces the smallest amount of recombination active defects at the interface but also the smallest change in surface band bending. (© 2010 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)