Patent ID: 7679381

Claim:
A probe for nondestructively characterizing electroluminescence and photoluminescence of a light-emitting material wafer, said wafer having plural layers including a top layer, intermediate layers and a substrate, said probe comprising: (a) a stage; (b) means for applying an electrical stimulus to a wafer of light-emitting material when said wafer is placed on said stage; (c) a first electrode proximate to said stage and in electrical connection with said applying means; (d) a second electrode proximate to said stage, in electrical connection with said applying means, and in spaced relation to said first electrode; (e) means for controlling first and second electrodes, said controlling means moving said first and said second electrodes with respect to said stage between a contact position and a not in contact position; and (f) means in electrical connection with said first and second electrodes for characterizing electroluminescence, wherein, when said wafer is on said stage and said first and second electrodes are moved by said controlling means temporarily to said contact position with respective areas of a top layer of said wafer, thereby defining instant light emitting diodes of said wafer associated with said first and said second electrodes, respectively, said applying means applying a forward bias to said instant light emitting diode associated with said first electrode and a reverse bias to said instant light emitting diode associated with said second electrode, and without damaging said wafer, said instant light emitting diodes being stimulated to electroluminescence from said areas of said wafer, and said characterizing means characterizes said electroluminescence.