Fig. 1. (a) Structure diagram of the E-type metal/Gr/GaN tunneling heterojunction UV photodetector; the upper left part is the polarized light transmission path. (b) Top diagram of the device. (c) Atomic force microscopy (AFM) image of 1 nm Al2O3 deposited on the GaN surface. (d) X-ray diffraction (XRD) pattern of the GaN/Al2O3 heterojunction. (e) Raman diagram of a single layer of graphene. (f) Energy band diagram of the device. (g) The polarization angle curve of the output photocurrent and incident light at −2 V for single layer Gr, GaN film, and Gr/Al2O3/GaN junction. (h) The variation curves of output photocurrent and incident light power density of E-metal/Gr/GaN tunneling heterojunction UV photodetectors under 0° and 90° polarized light at different bias. (i) 3D diagram of the optical response of E metal/Gr/GaN junction with polarization angle and bias.

Fig. 2. Polar curves of the polarization angle between the output photocurrent and the incident light of E-type metal (one)/Gr/Al2O3/GaN junction device under different bias voltages: (a) 0 V; (b) −2  V. (c) Polar coordinate curves of device integration under different bias voltages. Diagram of the polarization angle change between the output photocurrent and incident light: (d) 0 V; (e) −2  V. (f) Integration curve of the plane.

Fig. 3. E-type metal (one)/Gr/Al2O3/GaN junction device under different bias voltages, including output photocurrent, polarized light polar coordinates, and surface integral curves. (a), (d) −0.5  V; (b), (e) −1  V; (c), (f) −1.5  V.

Fig. 4. Real-time I-T curve of the output photocurrent with the deflection angle under different bias voltages. (a) 0 V; (b) −1  V; (c) −2  V.

Fig. 5. (a) At −2  V bias, the output photocurrent of one or two E-type metals deposited by the device varies with the polarization angle of the incident light. (b) Real-time I-T curves of the output optical response as a function of polarization angle for the E-metal (two)/Gr/Al2O3/GaN junction device at −2  V bias.

Fig. 6. Simulated near-field distribution of (a) E-type and (b) T-type metals in a unit cell at different polarization angles of incident light. |E| represents the intensity of the local electrical field.

Fig. 7. Polar coordinates of the polarization-sensitive photoelectric test with two E-type metal devices.

Fig. 8. (a) The variation curves of the output photocurrent and incident light power density of T-metal (two)/Gr/GaN tunneling heterojunction UV photodetectors under 0° and 90° polarized light at −2  V applied bias voltage. (b) 3D spectrum of the anisotropic optical response of the device with polarization angle and bias. (c) T-metal (two)/Gr/GaN tunneling heterojunction UV photodetectors at −2  V; the output light response changes with the polarization angle real-time I-T curve. The polar coordinate curve of the output photocurrent and polarization angle of the device under different bias voltages of (d) 0 V and (e) 0 to −2  V. (f) At −2  V bias, the output photocurrent of two and three T-type metals changes with the polarization angle of the incident light. (g)–(i) are plane curves corresponding to (d)–(f), respectively.

Fig. 9. Resonance mode of T-type metal at polarization angles of (a) 0°, (b) 90°. (c) The diagram of 45° polarized light decomposition is on the far left, and the corresponding calculation model is on the right.

Fig. 10. The photoelectric response characterization of the Gr/GaN tunneling heterojunction UV polarization sensitive photodetector. (a) I-V output curve under different optical power densities. (b) Corresponding log curves. (c) I-T output curve. (d) Individual I-T curves for amplification and normalization. At −2  V bias, the device (e) R, (f) D*, (g) LDR, (h) EQE, (i) S vary with incident light power density.