Approximately 500 mg of 1 was placed in a glass vial in a stainless-steel bubbler without a diptube for incoming carrier gas. The temperature of the bubbler was set at 120  C with a N2 flow of 100 sccm to aid transporting the precursor vapor into the deposition chamber. A 10 s N2 purge was used after the pulse of 1. The NH3 (AGA/Linde, 99.999 %) plasma used as the nitrogen source was an Ar (99.999 %, further purified with a getter filter to remove moisture)/NH3 (100/75 sccm) mixture, ignited using a plasma power of 2800 W. These plasma parameters was previously investigated to be optimal for our reactor and deposition of nitrides. A plasma pulse of 9 s followed by a 10 s purge was used with the above parameters unless otherwise stated. The thickness of the GaN film was 70 nm unless otherwise stated.