RU2323872C1 - STRUCTURE OF HETEROGENEOUS p-n JUNCTION BASED ON ZINC OXIDE NANOBARS AND SEMICONDUCTOR FILM - Google Patents

Abstract

FIELD: physics.

SUBSTANCE: within the structure of heterogeneous p-n junction based on at least one zinc oxide nanobar of n-type conductivity and semiconductor film of p-type conductivity mounted on a substrate, semiconductor film is made of nickel oxide and is placed directly on substrate or on upper edges of nanobars.

EFFECT: technical result of invention is production of improved junction.

5 cl, 7 dwg

Description

The invention relates to the field of micro- and nanoelectronics and can be used to develop new nanodevices based on the pn junction, such as photodetectors, sensors, field effect transistors, LEDs, etc.

A known heterogeneous pn junction structure consisting of epitaxial films of nickel oxide and zinc oxide (Hiromichi Ohta, Masao Kamiya, Toshio Kamiya, Masahiro Hirano, HideoHosono, UV-detector based on pn heterojunction diode composed of transparent oxide semiconductors, p-NiO / n- ZnO, Thin Solid Films, 445 (2003) 317-321).

However, the pn junction obtained on the basis of such a structure does not satisfy the requirements of modern technology.

A known prototype heterogeneous pn junction structure consisting of a p-type semiconductor film of p-type conductivity and n-type zinc oxide nanorods of conductivity is known. Zinc oxide nanorods are grown on a semiconductor film located on an aluminum oxide insulating substrate so that there are gaps between the nanorods that are filled with a dielectric to prevent shorting of the pn junction during the deposition of an electrical contact. The materials of the p-type semiconductor film were semiconductor III-V groups, II-VI and IV groups (Yi Gyu-Chul, Park Won-Il, pn heterojunction structure of zinc oxide - based nanorod and semiconductor thin film, preparation , and nanodevices filling same, WO 2004114422).

However, the manufacture of the above structure often leads to oxidation of the surface of a p-type semiconductor film of conductivity, which affects the properties of the pn junction.

The problem to which this invention is directed is to create a more perfect transition.

The technical result of which is to create a pn junction on more compatible with each other components, both of which are made only of oxides.

The problem is solved by the proposed structure of a heterogeneous pn junction based on at least one n-type zinc oxide nanorod and a p-type semiconductor film located on a substrate, the novelty of which is that the semiconductor film is made of nickel oxide and is either directly on the substrate, or on the upper ends of the nanorods.

Zinc oxide nanorods can be closed at their base to prevent shorting between the contact and the semiconductor film.

The structure of the heterogeneous p-n junction according to claim 1, characterized in that the diameter of the zinc oxide nanorod is 5-500 nm and the ratio of the length of the nanorod to its diameter is 2 or more.

The structure of the heterogeneous p-n junction according to claim 1, characterized in that the film thickness of Nickel oxide is 10-2000 nm.

The structure of the heterogeneous pn junction according to claim 1, characterized in that the substrate is made of a conductive, semiconductor or insulating material.

Figure 1-6 shows several variants of the General view of the proposed structure of a heterogeneous p-n junction, not limiting the invention.

1 to 2, the structure of the heterogeneous pn junction consists of a sequentially arranged substrate 1 deposited onto it a p-type nickel oxide semiconductor film 2, nanorods of n-type conductivity 3 grown on it and contacts to the nickel oxide film and oxide nanorods zinc 4. Moreover, in figure 1, the nanorods of zinc oxide 3 are located on the film of nickel oxide 2 with a gap, and in figure 2 are closed at its base.

4-6, the structure of the heterogeneous pn junction consists of a substrate 1, nanorods of n-type conductivity 3 grown on it, deposited p-type semiconductor nickel oxide film 2 on them, and contacts to the nickel oxide film and zinc oxide nanorods 4. Moreover, in FIGS. 3-4, the zinc oxide nanorods 3 are located on the substrate 1 with a gap, and in FIGS. 5-6 are closed at their base. In Figs. 3 and 5 (in the case of a semiconductor or insulating substrate), the contacts 4 to the zinc oxide nanorods 3 are connected directly to the nanorods, and in Figs. 4 and 6 (in the case of a conductive or semiconductor substrate), the contacts 4 are connected to the substrate 1.

The following example illustrates but does not limit the application of the present invention.

Example 1

A 50 nm thick nickel oxide film was deposited on a semiconductor substrate of single crystal silicon of orientation (100) by electron beam deposition. Then, zinc oxide nanorods with a diameter of 400-500 nm and a length to diameter ratio of 10-12 were grown on a nickel oxide film by gas phase deposition (FIG. 1). The quality (deterioration) of the pn junction both during the growth of zinc oxide nanorods and during the operation of the junction itself did not change. After that, contacts with copper wires were made to the nickel oxide film and to the zinc oxide nanorods using conductive glue.

Example 2

The same as in example 1, only the zinc oxide nanorods closed at the base (Figure 2), where their diameter was 250-300 nm, and the ratio of their length to diameter was 12-16. Furthermore, the film thickness of nickel oxide is 130 nm. After that, contacts with copper wires were made to the nickel oxide film and to the zinc oxide nanorods using conductive glue. Using these contacts, the current-voltage characteristic of the structure (Fig. 7) was measured in the dark and when irradiated with light with a wavelength of 420 nm. The shape of the curve of the current – voltage characteristic indicates the presence of a p – n junction between the nickel oxide film and the zinc oxide nanorods. An increase in the values of the current flowing through the structure upon irradiation with light with a wavelength of 420 nm indicates the sensitivity of the structure to light in the violet and ultraviolet range. The quality (deterioration) of the pn junction both during the growth of zinc oxide nanorods and during the operation of the junction itself did not change.

Example 3

A conductive film of titanium nitride was grown on an insulating alumina substrate by laser deposition. Then, zinc oxide nanorods with a diameter of 60-70 nm and a ratio of length to diameter of 90-100 were grown on it by gas-phase deposition. Then, by means of electron beam deposition, a nickel oxide film 500 nm thick was deposited on nanorods (Figure 3). After that, contacts with copper wires were made to the nickel oxide film and to the zinc oxide nanorods using conductive glue. Using these contacts, the current – voltage characteristic of the structure was measured in the dark and upon irradiation with light with a wavelength of 420 nm. The shape of the curve of the current – voltage characteristic indicates the presence of a p – n junction between the nickel oxide film and the zinc oxide nanorods. An increase in the values of the current flowing through the structure upon irradiation with light with a wavelength of 420 nm indicates the sensitivity of the structure to light in the violet and ultraviolet range. The quality (deterioration) of the pn junction both during the growth of zinc oxide nanorods and during the operation of the junction itself did not change.

Example 4

Same as in example 3, only zinc oxide nanorods closed at the base (Figure 5), where their diameter was 400-500 nm, and the ratio of their length to diameter was 50-60. Furthermore, the film thickness of nickel oxide is 1000 nm. The quality (deterioration) of the pn junction both during the growth of zinc oxide nanorods and during the operation of the junction itself did not change.

Example 5

Zinc oxide nanorods with a diameter of 70-80 nm (Figure 4) with a ratio of their length to diameter of 20-30 were grown on a conductive substrate of highly doped silicon with a specific resistance of 0.001 Ohm · cm by gas phase deposition. In this case, contact to the nanorods was carried out through the substrate. The nickel oxide film thickness was 1000 nm. The quality (deterioration) of the pn junction both during the growth of zinc oxide nanorods and during the operation of the junction itself did not change.

Example 6

The same as in example 5, only the zinc oxide nanorods closed at the base (Fig.6), where their diameter was 350-450 nm, and the ratio of their length to diameter was 25-35. The quality (deterioration) of the pn junction both during the growth of zinc oxide nanorods and during the operation of the junction itself did not change.

As can be seen from the above examples, the structure of the proposed pn junction allows using it to develop new, more advanced nanodevices.

Claims (5)

1. The structure of a heterogeneous pn junction based on at least one n-type zinc oxide nanorod and a p-type semiconductor film located on a substrate, characterized in that the semiconductor film is made of nickel oxide and is located either directly on substrate, or at the upper ends of the nanorods. 2. The structure of the heterogeneous pn junction according to claim 1, characterized in that the zinc oxide nanorods are closed at their base. 3. The structure of the heterogeneous pn junction according to claim 1, characterized in that the diameter of the zinc oxide nanorod is 5-500 nm and the ratio of the length of the nanorod to its diameter is 2 or more. 4. The structure of the heterogeneous pn junction according to claim 1, characterized in that the film thickness of nickel oxide is 10-2000 nm. 5. The structure of the heterogeneous pn junction according to claim 1, characterized in that the substrate is made of a conductive, semiconductor or insulating material.

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