Mn pinning effect in SrS thin-film electroluminescent phosphors

Abstract
An Mn pinning effect which limits the grain size in SrS:Mn thin films is reported. The SrS:Mn films exhibit spectrally identical saturated electroluminescent (EL) and photoluminescent (PL) green emissions at 5400 Å with CIE coordinates of x=0.33 and y=0.64. However, although strong PL emission was obtained, the EL emission was very weak. It is proposed that the weak EL emission is attributed to the small grain size caused by a Mn pinning effect. The mechanisms of the grain growth and Mn pinning effect in SrS are proposed and discussed in this letter.