Visible light emission from quantized planar Ge structures

Abstract
Visible photoluminescence has been observed near 1.9 eV at 300 K from quantized planar Ge structures. This is the first observation of luminescence in Ge and is similar to the recently reported luminescence from porous Si. The quantum structures are prepared from bulk Ge substrates, and both n- and p-type Ge produce luminescence at room temperature. These structures are fabricated by plasma-assisted etching using a CF4/O2 gas mixture.