Nanosecond cyclotron resonance in ultrapure diamond

Time-resolved cyclotron resonance on dislocation-free HPHT diamond

“…These values are shorter than that in the CVD diamond, 1100 ns (blue thin broken line). The faster rise time in each HPHT diamond was caused by the shorter carrier lifetime, as explained by an approximate formula for the rise time [11]. Similar decay behaviors were observed at the magnetic field resonated with heavy hole.…”

“…The incident pulse energy was less than 26 μJ corresponding to the incident photon density of b 5.9 × 10 15 photons/cm 3 . In such an excitation density achieved at the wavelength resonated with exciton absorption, carriers were generated by two-body collision of excitons as discussed in our previous paper [11]. Carrier density at the temporal peak after the pulse excitation was estimated to be 3 × 10 11 cm −3 from a spectral shift due to plasma effect.…”

“…We performed the TRCR measurement with an X-band EPR equipment (Bruker, ELEXSYS E580) under optical excitation with 5-ns laser pulses at the ultraviolet range, as described in our previous papers [9][10][11]17]. We examined two dislocation-free HPHT diamond crystals of single sector supplied by TISNCM (Russia): a (001)-oriented cylindrical crystal with 1 mm diameter and 1 mm thickness (abbreviated as (001)-HPHT diamond) and a (111)-oriented square substrate of 2 × 2 × 0.3 mm 3 (abbreviated as (111)-HPHT diamond).…”

“…We have so far measured time-resolved cyclotron resonance (TRCR) of optically injected carriers in high-purity diamond crystals with a time resolution of 13 ns [9][10][11]. The spectral analysis of CR below 40 K revealed definite effective masses and momentum relaxation times of electron and hole in diamond [9], and then enabled us to extract values of carrier drift mobilities [10].…”

Excitons and fundamental transport properties of diamond under photo‐injection

“…Second, the CR signal intensity increased as intensity squared of the incident laser light. These facts indicated that free carriers are generated as a result of a two‐body exciton process (). The density of excitons, estimated based on the incident photon density, was on the order of cm −3 .…”