DEPENDENCE OF CDZNSE ZNMGSSE LASER-DIODE OPERATING CHARACTERISTICS ONBAND-GAP AND NET ACCEPTOR CONCENTRATION OF P-TYPE CLADDING LAYER/

The dependence of CdZnSe/ZnMgSSe laser diode characteristics on the ba nd gap and net acceptor concentration of the cladding layer is investi gated theoretically to provide quantitative guidelines for cladding la yer design. Carrier overflow from the active layer to the cladding lay er and the recombination current at the active layer are calculated ta king into consideration band bending around the active layer. The calc ulated results are consistent with experimental and reported character istics. The improvement in laser diode characteristics due to the use of the superlattice cladding layer and ZnSe substrate is estimated by this calculation. The improvement due to the use of the ZnSe substrate is more effective when the cladding layer band gap is less than 2.95 eV, and the superlattice is more effective when the band gap is more t han 2.95 eV. It is shown that operating voltage of less than 5 V can b e achieved for a 490 nm laser diode when using a superlattice cladding layer.