In this study, multicolor photodetectors (PDs) fabricated by using bulk p-i-n-based visible GaAs and near-infrared InGaAs structures were monolithically integrated through a high-throughput epitaxial lift-off (ELO) process. To perform multicolor detection in integrated structures, GaAs PDs were transferred onto InGaAs PDs by using a Y₂O₃ bonding layer to simultaneously detect visible and near-infrared photons and minimize the optical loss. As a result, it was found that the GaAs top PD and InGaAs bottom PD were vertically aligned without tilting in x-ray diffraction (XRD) measurement. A negligible change in the dark currents for each PD was observed in comparison with reference PDs through electrical characterization. Furthermore, through optical measurements and simulation, photoresponses were clearly revealed in the visible and near-infrared band for the material’s absorption region, respectively. Finally, we demonstrated the simultaneous multicolor detection of the visible and near-infrared region,which implies individual access to each PD without mutual interference. These results are a significant improvement for the fabrication of multicolor PDs that enables the formation of bulk-based multicolor PDs on a single substrate with a high pixel density and nearly perfect vertical alignment for high-resolution multicolor imaging.

We report the fabrication of quantum dot infrared photodetectors (QDIPs) on silicon (Si) substrates by means of metal wafer bonding and an epitaxial lift-off process. According to the photoluminescence (PL) and x-ray diffraction measurements, the QDIP layer was transferred onto the Si substrate without degradation of the crystal quality or residual strain. In addition, from the PL results, we found that an optical cavity was formed because Pt/Au of the bonding material was served as the back mirror and the facet of the GaAs/air was served as the front mirror. The device performance capabilities were directly compared and peak responsivity was enhanced by nearly twofold from 0.038 A/W to 0.067 A/W.

High‐temperature operating performance of p – i – p quantum dots‐in‐a‐well infrared photodetectors (QDIPs) is successfully demonstrated. The optically active region consists of 10 layers of p ‐doped self‐assembled InAs quantum dots (QDs) asymmetrically positioned in In _0.15 Ga _0.85 As quantum wells (QWs). The dark current is suppressed by an incorporated superlattice (SL) structure composed of 10 pairs of AlGaAs/GaAs heterostructure. The very low recorded dark current makes the fabricated p – i – p QDIPs suitable for high‐temperature operation. The measured photoresponse reveals broad mid‐wave infrared (MWIR) detection up to 200 K.

We demonstrate flexible GaAs photodetector arrays that were hetero-epitaxially grown on a Si wafer for a new cost-effective and reliable wearable optoelectronics platform. A high crystalline quality GaAs layer was transferred onto a flexible foreign substrate and excellent retention of device performance was demonstrated by measuring the optical responsivities and dark currents. Optical simulation proves that the metal stacks used for wafer bonding serve as a back-reflector and enhance GaAs photodetector responsivity via a resonant-cavity effect. Device durability was also tested by bending 1000 times and no performance degradation was observed. This work paves a way for a cost-effective and flexible III-V optoelectronics technology with high durability.

In this letter, we have investigated electrical properties of metal-oxide-semiconductor (MOS) gate stack of Pt/Y ₂ O ₃ /In _0.53 Ga _0.47 As under different annealing conditions. We have found that proper annealing step significantly improves MOS interfacial properties of Pt/Y ₂ O ₃ /In _0.53 Ga _0.47 As MOS capacitors. Finally, we have realized MOS interface with a low density of trap state (D _it ) of 4 × 1012 eV ^-1 · cm ^-2 and hysteresis of 15 mV using postmetallization annealing at 350°C. Furthermore, we also first demonstrated In _0.53 Ga _0.47 As-on-insulator (-OI) transistors with Y ₂ O ₃ buried oxide layer using developed MOS interface. Fabricated In _0.53 Ga _0.47 As-OI transistors show good I-V characteristics and high peak mobility of ~2000 cm ² /Vs.