The investigation of electrical properties of long wavelength laser structures, produced via metal-organic chemical vapor deposition technique

The long wavelength InAs/InP and InAs/GaAs laser structures, containing quantum dot layers (QDs) mainly used in the fiber optic telecommunication industry. To examine the charge transfer characteristics, it carrried out by means of temperature-dependent current-voltage, temperature-dependent capacitance-voltage and electroluminescence measurements over InAs/InP, and InAs/GaAs based p-i-n structures. For InAs/InP structure, tunneling and generation-recombination carrier conduction mechanisms were identified within a junction bias voltage of 0–0.6 V. Above 0.6 V, Poole–Frenkel was the actual path in conduction and the mobility of carrier was determined quantitatively by means of temperature-dependent current-voltage curves in the space charge bias region. A thermal energy gap of 0.8 eV corresponded to the band gap of quantum dash. Meanwhile, for InAs/GaAs structure, tunneling kind transport was exhibited in both forward and reverse bias voltage directions. Temperature- and field-dependent electron and hole mobilities were simultaneously derived from admittance measurements on an InP/InGaAsP/InAs/InPlong wavelength laser structure. Each carrier's mobility was separated in the frequency domain due to the corresponding different relaxation times from C versus logf curves. Derived electron and hole mobilities followed the Poole–Frenkeltype field dependence, indicating the transport of carriers through hopping. Extracted thermal energy gap and disorder temperature values were in mutual agreement with previous current density–voltage measurements and from the energy band diagram of the present structure, constructed from other studies in the literature by photoluminescence and photoluminescence excitation experiments. From the electroluminescence measurement, the onset of light took place when the forward bias exceeded 1.3 V for InAs/InP p-i-n structure through electroluminescence measurements, while the onset of light took place when the forward bias exceeded 3 V for InAs/GaAs p-i-n structure through electroluminescence measurements. The peak value of emitted laser light for InAs/InP QDashes and InAs/GaAs QDs occurred in 1.55 um and 1.3 um, respectively.