Mg doping of InGaN layers grown by PA-MBE for the fabrication of Schottky barrier photodiodes

J Pereiro (1) , A Redondo-Cubero (1, 2) , S Fernandez-Garrido (1) , C Rivera (1) , A Navarro (1) , E Muñoz (1) , E Calleja (1) , R Gago (3) , Juan Pereiro

1 Instituto de Sistemas Optoelectrónicos y Microtecnología
2 Centro de Micro-Análisis de Materiales
3 Instituto de Sistemas Optoelectrónicos y Microtecnología

This work reports on the fabrication of Schottky barrier based Mg-doped (In, Ga)N layers for fluorescence applications. Mg acceptors are used in order to compensate surface and bulk donors that prevent the fabrication of Schottky contacts on unintentionally doped (In, Ga)N layers. Rectifying properties of the contacts exhibited a major improvement when (In, Ga)N:Mg is used. The electrical and optical measurements of the layers showed a hole concentration up to 3×10 19 holes/cm 3 with a Mg acceptor activation energy of ~60 meV. Backilluminated photodiodes fabricated on 800 nm thick Mg-doped In 0.18 Ga 0.82 N layers exhibited a band pass photo-response with a rejection ratio >10 2 between 420 nm and 470 nm and peak responsivities of 87 mA/W at ∼470 nm. The suitability of these photodiodes for fluorescence measurements was demonstrated.

Mots clés: : 68.35.bg; 85.30.De; 85.60.Gz; 81.15.Hi

J Pereiro, A Redondo-Cubero, S Fernandez-Garrido, C Rivera, A Navarro, et al.. Mg doping of InGaN layers grown by PA-MBE for the fabrication of Schottky barrier photodiodes. Journal of Physics D: Applied Physics, 2010, 43 (33), pp.335101. ⟨10.1088/0022-3727/43/33/335101⟩. ⟨hal-00569675⟩