Enhancement of Er3+ Luminescence from Er-doped Hydrogenated Amorphous Silicon by Carbon Co-doping

Abstract

The effect of C co-doping on the Er3+ luminescence properties of Er-doped hydrogenated amorphous Si (a-Si:H) is investigated. Er-doped a-Si:H thin films co-doped with C were deposited using electron–cyclotron resonance plasma enhanced chemical vapor deposition of SiH4 and CH4 with concurrent sputtering of Er. We find that C co-doping greatly increases the room temperature 1.54 µm Er3+ photoluminescence (PL) intensity, with the maximum enhancement by a factor of 4 being obtained at a C concentration of ∼15 at.%. Part of the reason for such enhancement is the suppression of the temperature quenching of the Er3+ PL intensity and liftime, which we attribute to the increased optical bandgap of a-Si:H due to C co-doping. However, unlike other co-dopants such as O that also can enhance the Er3+ PL, C co-doping does not degrade the a-Si:H film quality, demonstrating its suitability for developing Si-based optoelectronic devices.