1. IBPOWER Kick off meeting – 07/02/08 Specific issues relating to plasma-MBE Growth under group III-rich versus group V-rich conditions Control of composition is different from conventional MBE growth Strong polarisation fields for wurtzite nitrides Controlled p-doping of InGaN

2. IBPOWER Kick off meeting – 07/02/08 GaN MBE growth kinetics Heying et al, Appl Phys Lett 77 (2000) 2885 In would be similar, but at a lower temp.

3. IBPOWER Kick off meeting – 07/02/08 Growth under N-rich conditions

4. IBPOWER Kick off meeting – 07/02/08 Growth under optimum conditions

5. IBPOWER Kick off meeting – 07/02/08 Composition control Conventional MBE:- fix In:Ga ratio and use excess group V flux For plasma MBE under group III rich conditions:- fix Ga:N ratio and use excess In – excess In will re-evaporate

6. IBPOWER Kick off meeting – 07/02/08 Controlled doping of InGaN? Recent evidence at ICNS7 for InN p-n junction In may enhance Mg solubility in InGaN Depth of Mg in InGaN may be < 200meV Influence of inversion and accumulation layers at the surface Veal et al JCG 288 (2006) 268 For InN there is strong electron accumulation at the surface due to pinning of the Fermi energy high in the conduction band – This will be an issue for P-doping

7. IBPOWER Kick off meeting – 07/02/08 Polarisation fields In GaN the polarisation fields enhance electron and hole mobility to the surface and substrate In-rich InGaN will be very different due to the surface accumulation layer

8. IBPOWER Kick off meeting – 07/02/08 Proposed programme- questions? What In content should we aim for initially? The calculations suggest the Mn level is optimum for 15% Ga is that correct? What are the optimum thicknesses for the P-i-N layers? Should the top contact be graded towards a higher band- gap to ensure photons are absorbed in the Mn doped InGaN region? Choice of substrate – sapphire, GaAs or GaN templates? Should we consider cubic InGaN as an alternative?

9. IBPOWER Kick off meeting – 07/02/08 Initial growth programme Growth of InGaN with the correct In content and correct polarity using AlN buffer layers. P & N-doping of InGaN with Mg and Si Mn doping of InGaN P-i-N structures with and without Mn Initial layers available for etching studies by partners