Room-temperature green luminescence and lasing of thin CdS films on glass formed by pulsed laser-deposition

Green emitting lasers on the basis of thin films operating at 300 K are needed for numerous tasks, such as the realization of sophisticated optical circuits on single substrates. Hence, the requirements of thin film materials with excellent emission properties are rapidly growing. From all common semiconductors, the most green emission is theoretically expected from the II-VI compound CdS owing to its bandgap at 500 nm. However, thin film CdS does not exhibit bandgap emission at 300 K due to various reasons. We present thin CdS films formed by pulsed-laser-deposition (PLD), which exhibit bandgap photoluminescence and lasing at 300 K.