ZnS:Mn交流电致发光的效率与Mn浓度的关系和浓度猝灭

从实验上确定了交流电致发光薄膜Y2O3-ZnS:Mn-Y2O3的发光效率与Mn浓度的关系:在低浓度下(10-5～10-4g/g),发光效率随Mn浓度线性增加,在10-3g/g附近发光效率达到最大值,当Mn浓度继续增加时,发光效率开始下降.在ZnS:Mn薄膜中存在两种发光中心—单个Mn中心和Mn对,它们的衰减都是指数形式,它们激发态的寿命随Mn浓度增加而减.Mn对发光中心与单个Mn中心之比随Mn浓度增加而增加.从而减少了有效的发光中心数目,这是浓度猝灭的原因之一.发光效率在高Mn浓度时下降的另外原因是由于电隅极子之间共振能量传递引起浓度猝灭.

RELATION OF EFFICIENCY OF ACEL IN ZnS:Mn THIN FILMS WITH THE Mn CONCENTRATION AND CONCENTRATION QUENCHING

The thin films Y2O3-ZnS:Mn-Y2O3 give ACEL with brightness as high as 5000 nit but its efficiency is low(10-3~10-4W/W).The aim of the present work is to find the relation of efficiency of ACEL in ZnS:Mn thin film with the Mn concentration and the origin of concentration quenching.Taking six ZnS:Mn raw materials with Mn concentration varying from 1.5×10-4g/g to 5×10-2g/g,we evaporate them in vacuum ~10-5onto conducting glass to form Y2O3-ZnS:Mn-Y2O3 ACEL thin film.The Mn concentration in these ZnS:Mn thin films varies only by five times(2.7×10-5 to 1.3 ×10-4g/g).In the range of the Mn concentration from 2.7×10-5 to 1.3×10-4g/g,the efficiency of ACEL increases with the Mn concentration.