Intrinsic quantum dots in partially ordered bulk (GaIn)P

We present a photoluminescence study with 500 nm lateral resolution on partially ordered bulk (GaIn)P alloys at lattice temperatures 3-60 K, external magnetic fields 0-12 T, and excitation power 0.1-100 mu W. In the known ordering-induced low energy emission band we resolve narrow optical transition lines with 0.3-1.0 meV width. They show no thermal broadening, a diamagnetic shift with pronounced anisotropy, and biexci-tonic states. We demonstrate that the transitions are connected with intrinsic quasi-zero-dimensional electron-hole confinement formed at the antiphase-boundaries in the crystal.