Applied Physics A

, Volume 112, Issue 3, pp 561-567

First online:

Near-IR photoluminescence from Si/Ge nanowire-grown silicon wafers: effect of HF treatment

  • Seref KalemAffiliated withNational Research Institute of Electronics and Cryptology TÜBITAK-BILGEM Email author 
  • , Peter WernerAffiliated withDepartment of Experimental Physics, Max Planck Institute
  • , Vadim TalalaevAffiliated withDepartment of Experimental Physics, Max Planck InstituteZIK ‘SiLi-nano’, Martin-Luther-Universität (Halle)

Rent the article at a discount

Rent now

* Final gross prices may vary according to local VAT.

Get Access


We present the room-temperature near-infrared (NIR) photoluminescence (PL) properties of Si/Ge nanowire (NW)-grown silicon wafers which were treated by vapor of HF:HNO3 chemical mixture. This treatment activates or enhances the PL intensity in the NIR region ranging from 1000 nm to 1800 nm. The PL consists of a silicon band-edge emission and a broad composite band which is centered at around 1400–1600 nm. The treatment modifies the wafer surface particularly at defect sites especially pits around NWs and NW surfaces by etching and oxidation of Si and Ge. This process can induce spatial confinement of carriers where band-to-band (BB) emission is the dominant property in Si-capped strained Si/Ge NW-grown wafers. Strong signals were observed at sub-band-gap energies in Ge-capped Si/Ge NW-grown wafers. It was found that NIR PL is a competitive property between the Si BB transition and deep-level emission, which is mainly attributable to Si-related defects, Ge dots and strained Ge layers. The enhancement in BB and deep-level PL is discussed in terms of strain, oxygen-related defects, dot formation and carrier-confinement effects. The results demonstrate the effectiveness of this method in enhancing and tuning NIR PL properties for possible applications.