Laser vibrational excitation of radicals to prevent crystallinity degradation caused by boron doping in diamond

Abstract

Pursuing high-level doping without deteriorating crystallinity is prohibitively difficult but scientifically crucial to unleashing the hidden power of materials. This study demonstrates an effective route for maintaining lattice integrity during the combustion chemical vapor deposition of highly conductive boron-doped diamonds (BDDs) through laser vibrational excitation of a growth-critical radical, boron dihydride (BH2). The improved diamond crystallinity is attributed to a laser-enabled, thermal nonequilibrium suppression of the relative abundance of boron hydrides (BH), whose excessive presence induces boron segregation and disturbs the crystallization. The BDDs show a boron concentration of 4.3 × 1021 cm−3, a film resistivity of 28.1 milliohm·cm, and hole mobility of 55.6 cm2 V−1 s−1, outperforming a commercial BDD. The highly conductive and crystalline BDDs exhibit enhanced efficiency in sensing glucose, confirming the advantages of laser excitation in producing high-performance BDD sensors. Regaining crystallinity with laser excitation in doping process could remove the long-standing bottlenecks in semiconductor industry.

Influence of B/N co-doping on electrical and photoluminescence properties of CVD grown homoepitaxial diamond films

“…The B doping concentration in insulating diamond defines its ability of conductivity, for instance at the doping concertation of∼10 18 cm −3 the insulating diamond transforms to semiconducting diamond [19], whereas insulating diamond converts to metallic at the B doping concentration above 10 21 cm −3 [20]. However, the high doping of B causes the degradation of the crystalline quality of the diamond and around 10 % of doped B atoms could not act as acceptors [21,22]. Moreover, B doping is most effective and has shown higher conductivity in large diamond crystals (microcrystalline diamond) than in smaller nanodiamond grains [23].…”