CN100510204C - Lithium niobate pn junction and preparation method thereof - Google Patents

Abstract

The lithium niobate pn junction is formed with two types of lithium niobate crystal with different carrier types, and has the crystal chemistry expression of p:LiNbO3/n:LiNbO3, where, p is one or composition of Mg, In, Zn, Hf, Zr and other doped elements, and n is one or composition of Fe, Cu, Mn, Ce and other doped elements. It is prepared through the following steps: crystal pulling procedure to grow p:LiNbO3 crystal, slicing into p:LiNbO3 chip as the liquid phase epitaxy substrate; compounding powder material for n:LiNbO3, heating to melt and lowering the temperature to the smelting point; roasting the substrate, epitaxial growth inside the melt to form epitaxial chip, drawing the epitaxial chip from the melt and cooling to room temperature; and polishing to obtain the lithium niobate pn junction. The lithium niobate pn junction with excellent photoelectronic performance and rectification characteristic may be used as integrated optoelectronic platform.

Description

Lithium niobate pn junction and preparation method thereof

[technical field]: the invention belongs to the photoelectric material technical field.

[background technology]: Lithium niobium trioxide (LiNbO ₃) crystal is a kind of current collection light, acousto-optic, piezoelectricity, non-linear, effect artificial lens such as light is sold off, especially implement to present different physicalies after different the doping, it is the crystal that the photonics performance is maximum, overall target is best that people found so far, be considered to one of the main candidate material of " optics silicon ", have a wide range of applications at aspects such as surface wave filter, Electro-optical Modulation, electrooptical switching, optical waveguides and laser apparatus thereof, frequency multiplication, high density information storages.

Various be in the electron device of platform with silicon materials, pn knot is playing of paramount importance effect.No matter be diode originally, or triode, and more complicated unicircuit, the pn knot all is essential, the most basic.We can say there is not the invention of pn knot, just do not have the information age.Yet up to the present, also not about the report of the pn knot of the lithium niobate crystals that is known as " optics silicon " material.If can realize the pn knot in lithium niobate crystals, electro-optical properties that lithium niobate crystals is good and pn knot organically combine, and make it to become the platform of integrated optoelectronics, will have breakthrough meaning.

[summary of the invention]: the object of the invention provides lithium niobate pn junction of a kind of " optics silicon " material and preparation method thereof.It is to utilize liquid phase epitaxial method, with the Crystal Growth of Lithium Niobate of different carrier types together, forms the pn knot, make its have forward conduction, oppositely by rectification characteristic.

Lithium niobate pn junction of the present invention is that its crystal chemistry formula can be expressed as: p:LiNbO with the Crystal Growth of Lithium Niobate of two kinds of different carrier types together ₃/ n:LiNbO ₃, wherein, p is one or more the combination in the anti-photorefraction doped elements such as magnesium, indium, zinc, hafnium, zirconium, n is one or more the combination in the refraction doped elements of light such as iron, copper, violent, cerium.P:LiNbO ₃In, when p is magnesium, doping 〉=4.6mol%; When p is zinc, doping 〉=6.5mol%; When p is indium, doping 〉=3.0mol%; When p is hafnium, doping 〉=4.0mol%; When p is zirconium, doping 〉=2.0mol%; When p was the combination of magnesium, zinc, indium, hafnium, zirconium, the doping of establishing magnesium was that the doping of x mol%, zinc is that the doping of y mol%, indium is that the doping of z mol%, hafnium is that the doping of u mol%, zirconium is v mol%, then $\frac{x}{4.6}+\frac{y}{6.5}+\frac{z}{3.0}+\frac{u}{4.0}+\frac{v}{2.0}\≥1.0.$ N:LiNbO ₃Doping 〉=0.01wt% of middle n.

The concrete preparation method of lithium niobate pn junction of the present invention comprises the steps:

The first, use Czochralski grown p:LiNbO ₃Crystal through operations such as annealing, poling, orientation, cutting, grinding and polishings, can get 1mm polishing both surfaces p:LiNbO ₃Wafer is as the substrate of rheotaxy;

The second, preparation n:LiNbO ₃Powder, thorough mixing is 24 hours on mixer, 850 ℃ of constant temperature 2 hours, 1100 ℃ of calcinings 2 hours;

Three, the powder in second step is put into platinum crucible, be warming up to 1280 ℃, constant temperature 13h is cooled to fusing point with the speed of 10～20 ℃/h with melt; Substrate roasting 0.5～3h with in the first step puts into the melt epitaxy, time 1～5min; Epitaxial wafer is detached bath surface 2～5mm; Speed with 20～50 ℃/h is cooled to room temperature;

Four, with epitaxial wafer single-sided polishing to the 0.3～0.5mm in the 3rd step, can get lithium niobate pn junction.

Lithium niobate pn junction provided by the invention can be applied to the photoelectron technology field.

Advantage of the present invention and positively effect:

Lithium niobate pn junction of the present invention possesses forward conduction arranged, oppositely by rectification characteristic, electro-optical properties that it is good with lithium niobate crystals and pn knot organically combine, make it to become the platform of integrated optoelectronics, have breakthrough meaning and huge market outlook.Typical volt-ampere curve as shown in Figure 1.Wherein forward is p:LiNbO ₃Connect positive source, n:LiNbO ₃Connect power cathode; Be reversed p:LiNbO ₃Connect power cathode, n:LiNbO ₃Connect positive source.Though the forward voltage of this pn knot is higher, electric current is less, believes along with the improving constantly of technology its prospect that will have a very wide range of applications aspect integrated optoelectronics.

Outstanding substantial characteristics of the present invention and positively effect can be embodied from following embodiment, but they are not that the present invention is imposed any restrictions.

[description of drawings]:

Fig. 1 is the lithium niobate pn junction rectification characteristic curve.

[embodiment]:

Embodiment 1:

(1) with Czochralski grown Mg (5mol%): LiNbO ₃Crystal through operations such as annealing, poling, orientation, cutting, grinding and polishings, can get 1mm polishing both surfaces Mg:LiNbO ₃Wafer is as the substrate of rheotaxy.(2) preparation Fe (0.05wt%): LiNbO ₃Powder, thorough mixing is 24 hours on mixer, 850 ℃ of constant temperature 2 hours, 1100 ℃ of calcinings 2 hours.(3) powder of above-mentioned processing is put into platinum crucible, be warming up to 1280 ℃, constant temperature 13h is cooled to 1250 ℃ with the speed of 15 ℃/h with melt; With substrate roasting 0.5h, put into melt and grow, time 2min; Substrate is detached bath surface 5mm; Speed with 40 ℃/h is cooled to room temperature.(4) with above-mentioned epitaxial wafer single-sided polishing to 0.5mm, can get lithium niobate pn junction.

Embodiment 2:

(1) with Czochralski grown In (4mol%): LiNbO ₃Crystal through operations such as annealing, poling, orientation, cutting, grinding and polishings, can get 1mm polishing both surfaces In:LiNbO ₃Wafer is as the substrate of rheotaxy.(2) preparation Cu (0.08wt%): LiNbO ₃Powder, thorough mixing is 24 hours on mixer, 850 ℃ of constant temperature 2 hours, 1100 ℃ of calcinings 2 hours.(3) powder of above-mentioned processing is put into platinum crucible, be warming up to 1280 ℃, constant temperature 13h is cooled to 1250 ℃ with the speed of 15 ℃/h with melt; With substrate roasting 0.5h, put into melt and grow, time 3min; Substrate is detached bath surface 4mm; Speed with 30 ℃/h is cooled to room temperature.(4) with above-mentioned epitaxial wafer single-sided polishing to 0.4mm, can get lithium niobate pn junction.

Embodiment 3:

(1) with Czochralski grown Hf (4mol%): LiNbO ₃Crystal through operations such as annealing, poling, orientation, cutting, grinding and polishings, can get 1mm polishing both surfaces Hf:LiNbO ₃Wafer is as the substrate of rheotaxy.(2) preparation Mn (0.1wt%): LiNbO ₃Powder, thorough mixing is 24 hours on mixer, 850 ℃ of constant temperature 2 hours, 1100 ℃ of calcinings 2 hours.(3) powder of above-mentioned processing is put into platinum crucible, be warming up to 1280 ℃, constant temperature 13h is cooled to 1250 ℃ with the speed of 15 ℃/h with melt; With substrate roasting 0.5h, put into melt and grow, time 5min; Substrate is detached bath surface 3mm; Speed with 50 ℃/h is cooled to room temperature.(4) with above-mentioned epitaxial wafer single-sided polishing to 0.3mm, can get lithium niobate pn junction.

Embodiment 4:

(1) with Czochralski grown Zn (4mol%), In (2mol%): LiNbO ₃Crystal through operations such as annealing, poling, orientation, cutting, grinding and polishings, can get 1mm polishing both surfaces In:LiNbO ₃Wafer is as the substrate of rheotaxy.(2) preparation Cu (0.02wt%), Ce (0.08wt%): LiNbO ₃Powder, thorough mixing is 24 hours on mixer, 850 ℃ of constant temperature 2 hours, 1100 ℃ of calcinings 2 hours.(3) powder of above-mentioned processing is put into platinum crucible, be warming up to 1280 ℃, constant temperature 13h is cooled to 1250 ℃ with the speed of 10 ℃/h with melt; With substrate roasting 1h, put into melt and grow, time 4min; Substrate is detached bath surface 5mm; Speed with 20 ℃/h is cooled to room temperature.(4) with above-mentioned epitaxial wafer single-sided polishing to 0.5mm, can get lithium niobate pn junction.

Claims (3)

1, a kind of lithium niobate pn junction is characterized in that it is grown in the Lithium niobium trioxide of hole and two kinds of different carrier types of electronics together, and its crystal chemistry formula is expressed as: p:LiNbO ₃/ n:LiNbO ₃, wherein, p is one or more the combination in magnesium, indium, zinc, hafnium, the zirconium anti-photorefraction doped element, n is one or more the combination in iron, copper, manganese, the refraction doped element of cerium light; P:LiNbO ₃In, when p is magnesium, doping 〉=4.6mol%; When p is zinc, doping 〉=6.5mol%; When p is indium, doping 〉=3.0mol%; When p is hafnium, doping 〉=4.0mol%; When p is zirconium, doping 〉=2.0mol%; When p was the combination of magnesium, zinc, indium, hafnium, zirconium, the doping of establishing magnesium was that the doping of x mol%, zinc is that the doping of y mol%, indium is that the doping of z mol%, hafnium is that the doping of u mol%, zirconium is v mol%, then $\frac{x}{4.6}+\frac{y}{6.5}+\frac{z}{3.0}+\frac{u}{4.0}+\frac{v}{2.0}\≥1.0,$ N:LiNbO ₃Doping 〉=0.01wt% of middle n.

2, the preparation method of the said lithium niobate pn junction of claim 1 is characterized in that this method comprises the steps:

The first, use Czochralski grown p:LiNbO ₃Crystal through operations such as annealing, poling, orientation, cutting, grinding and polishings, gets 1mm polishing both surfaces p:LiNbO ₃Wafer is as the substrate of rheotaxy;

The second, preparation n:LiNbO ₃Powder, thorough mixing is 24 hours on mixer, 850 ℃ of constant temperature 2 hours, 1100 ℃ of calcinings 2 hours;

Three, the powder in second step is put into platinum crucible, be warming up to 1280 ℃, constant temperature 13h is cooled to fusing point with the speed of 10～20 ℃/h with melt; Substrate roasting 0.5～3h with in the first step puts into the melt epitaxy, time 1～5min;

Epitaxial wafer is detached bath surface 2～5mm; Speed with 20～50 ℃/h is cooled to room temperature;

Four, with epitaxial wafer single-sided polishing to the 0.3～0.5mm in the 3rd step, can get lithium niobate pn junction.

3, the application of the said lithium niobate pn junction of claim 1 is characterized in that it is used for the photoelectron technology field.

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