Boron-doped superlattices and Bragg mirrors in diamond

Abstract

International audienceA periodic modulation of the boron doping level of single crystal diamond multilayers over more than three orders of magnitude during epitaxial growth by microwave plasma-enhanced chemical vapor deposition is shown to yield Bragg mirrors in the visible. The thicknesses and doping level of the individual layers were controlled by in situ spectroscopic ellipsometry, enabling to tune the reflec-tance peak to the wavelength range of diamond color centers, such as NV 0 or NV À . The crystalline quality, periodicity, and sharpness of the doping transitions in these doping superlattices over tens of periods were confirmed by high resolution X-ray diffraction

Relaxation of the resistive superconducting state in boron-doped diamond films

“…The other difference between the two samples was the duration of the growth, leading to thicknesses d of 300 and 70 nm for samples N1 and N2, respectively. Four 064506-4 parallel silver-paste contacts drawn across the whole sample were used to measure the sheet resistance R of the film at 300 K, and the thickness was deduced from spectroscopic ellipsometry measurements [36] performed in situ [37]. This allowed the determination of the resistivity ρ = R d, which was very similar for both samples.…”

In situ spectroscopic ellipsometry monitoring of diamond multilayers grown by microwave plasma enhanced chemical vapor deposition

“…Thus, contrary to a large number of materials, the very first ex situ measurement to precisely assess the thickness and doping level of boron doped diamond monolayers was only demonstrated in 2013 [17]. Recently, the same technique has been used in situ on the reactor to monitor in real time the fabrication of Bragg mirrors [5].…”

“…As mentioned elsewhere [5], the substrate, considered as a semi-infinite medium, and the nid diamond layers of finite thickness, could be simulated by a Cody-Lorentz model. In this latter one, the direct E'0 and indirect Eg ID band gap absorptions of diamond were simulated by fixing the energy of the principal oscillator at 7.3 eV and adjusting the amplitude and the tail of the Lorentzian contribution whereas the E2 peak absorption was taken into account by fixing the UV Pole energy at 11 eV.…”

“…The fabrication of diamond-based power or optical devices such as n/i/p and Schottky pseudo-vertical diodes [1][2][3] or Bragg mirror [4,5], requires the growth of boron-doped and intrinsic diamond layers with steep interfaces, well-controlled thicknesses and doping level. In most cases, an optimization of the growth conditions is needed, requiring the growth of a large number of samples and the use of destructive and time-consuming techniques such as Secondary…”

Diamond Bragg superlattice grown in microwave gas discharge for obtaining photoluminescence of single diamond color centers comprising a dense 3D ensemble

“…So, nowadays the only way to create a highly reflective CVD diamond Bragg superlattice is the modulation doping method consisting in the growth of interchanging highly and low doped CVD diamond layers [2,3] (please see fig. 1).…”