Provided is a piezoelectric element including a first electrode provided above a substrate, a piezoelectric layer including a plurality of crystal grains containing potassium, sodium, and niobium and provided above the first electrode, and a second electrode provided above the piezoelectric layer. An atom concentration N.sub.K1 (atm %) of potassium contained in grain boundaries of the crystal grains and an atom concentration N.sub.K2 (atm %) of potassium contained in the crystal grains satisfy a relationship of 1.0<N.sub.K1/N.sub.K2≤2.4.

A lead-free KNN-based piezoelectric material represented by the composition formula (K.sub.aNa.sub.bLi.sub.c)(Nb.sub.dTa.sub.eSb.sub.f)O.sub.g, where 0.4≤a≤0.5, 0.5≤b≤0.6, 0.01≤c≤0.1, 0.5≤d≤1.0, 0.05≤e≤0.15, 0.01≤f≤0.09, 1≤g≤3. In one embodiment, the lead-free KNN-based piezoelectric material has a d.sub.33>300 pm/V and a T.sub.curie>250° C. In one embodiment, the d.sub.33 and T.sub.curie of the lead-free textured KNN-based piezoelectric material can be adjusted by creating phase boundaries of (i) orthorhombic to tetragonal (O-T), (ii) rhombohedral to orthorhombic (R-O), and (iii) orthorhombic to tetragonal (O-T). In one embodiment, the lead-free KNN-based piezoelectric material is textured with NaNbO.sub.3 or Ba.sub.2NaNb.sub.5O.sub.15 seeds which are platelet or acicular shaped. In one embodiment, the amount, orientation, or particle size distribution of the NaNbO.sub.3 or Ba.sub.2NaNb.sub.5O.sub.15 texturing seeds in the lead-free textured KNN-based piezoelectric material can be altered.

The present invention makes clear and defines a congruent composition of a langasite-based oxide, and establishes a method of manufacturing a crystal by any desired composition of AE.sub.3ME.sub.1+a(Ga.sub.1−xAl.sub.x).sub.3+bSi.sub.2+cO.sub.14 (AE is an alkaline-earth metal, ME is Nb or Ta, 0≤x≤1, −0.5<a≤0 or 0<a<0.5, −0.5<b≤0 or 0<b≤0.5, and −0.5<c≤0 or 0<c<0.5, excluding a=b=c=0). This makes it possible to suppress the formation of an impurity, and improve the yield and crystal manufacturing rate. The raw material is a raw material mixture prepared by mixing an alkaline-earth metal or its carbonate or oxide, Nb or Ta or its oxide, Ga or its oxide, Al or its oxide, and Si or its oxide.

A method of manufacturing a monocrystalline layer comprises the following successive steps: providing a donor substrate comprising a piezoelectric material of composition ABO.sub.3, where A consists of at least one element from among Li, Na, K, H, Ca; and B consists of at least one element from among Nb, Ta, Sb, V; providing a receiver substrate, transferring a layer called the “seed layer” from the donor substrate on to the receiver substrate, such that the seed layer is at the bonding interface, followed by thinning of the donor substrate layer; and growing a monocrystalline layer of composition A′B′O.sub.3 on piezoelectric material ABO.sub.3 of the seed layer, where A′ consists of a least one of the following elements Li, Na, K, H; B′ consists of a least one of the following elements Nb, Ta, Sb, V; and A′ is different from A or B′ is different from B.

A method of manufacturing a monocrystalline layer, comprises the following successive steps: providing a donor substrate comprising a piezoelectric material of composition ABO.sub.3, where A consists of at least one element from among Li, Na, K, H, Ca; and B consists of at least one element from among Nb, Ta, Sb, V; providing a receiver substrate, transferring a layer called the “seed layer” from the donor substrate on to the receiver substrate, such that the seed layer is at the bonding interface, followed by thinning of the donor substrate layer; and growing a monocrystalline layer of composition A′B′O.sub.3 on piezoelectric material ABO.sub.3 of the seed layer where A′ consists of a least one of the following elements Li, Na, K, H; B′ consists of a least one of the following elements Nb, Ta, Sb, V; and A′ is different from A or B′ is different from B.

Described herein are aspects of a three-dimensional (3D) piezoelectric structure that can be composed of a 3D periodic microlattice that can be composed of a piezoelectric composite material, wherein the 3D periodic microlattice can include a plurality of interconnected 3D node units capable of generating a piezoelectric response upon application of a stress to the 3D periodic microlattice, and wherein the plurality of interconnected 3D node units can form a tailored piezoelectric tensor space. Also described herein are systems that can include one or more of the 3D piezoelectric structures described herein. Also described herein are methods of making and using the 3D piezoelectric structures described herein.

A method for fabricating nano-electro-mechanical tags for identification and authentication includes, in part, forming a protective layer above a substrate, forming a first conductive layer above the protective layer serving as a first electrode, forming a piezoelectric layer above the first conductive layer, forming a second conductive layer above the piezoelectric layer, patterning the second conductive layer to form a second electrode, patterning the piezoelectric layer to expose one or more portions of the first conductive layer, and forming one or more trenches that extends into a plurality layers formed above. In addition, a sacrificial layer can be formed above portions of the substrate, and the sacrificial layer can be removed by etching to release the nano-electro-mechanical tags from the substrate.

The invention relates to an optoelectronic device (1) comprising: at least one diode (2) that has a semiconductor portion (20) in which a PN or PIN junction is formed; a peripheral conductive layer (40) that extends in the main plane in such a way as to surround the semiconductor portion (20); a peripheral piezoelectric portion (30) that extends in the main plane in such a way as to surround the semiconductor portion (20); a first polarizing electric circuit (30) capable of generating an electric field in the peripheral piezoelectric portion (30) by applying an electric potential at least to the peripheral conductive layer (40) so as to induce a deformation of the peripheral piezoelectric portion (30) in the direction of the main plane, thus causing a tensile deformation of the semiconductor portion (20) in the main plane.

A subtractive forming method that includes providing a material stack including a samarium and selenium containing layer and an aluminum containing layer in direct contact with the samarium and selenium containing layer. The samarium component of the samarium and selenium containing layer of the exposed portion of the material stack is etched with an etch chemistry comprising citric acid and hydrogen peroxide that is selective to the aluminum containing layer. The hydrogen peroxide reacts with the aluminum containing layer to provide an oxide etch protectant surface on the aluminum containing layer, and the citric acid etches samarium selectively to the oxide etch protectant surface. Thereafter, a remaining selenium component of is removed by elevating a temperature of the selenium component.

A transceiver device for receiving an interrogation signal at a first carrier frequency and for transmitting a response signal at a second carrier frequency is disclosed. The interrogation signal comprises the first carrier frequency modulated at the second carrier frequency. The communication device includes a sensor coupled to a demodulator. The sensor receives a low frequency input used to further modulate the interrogation signal. The demodulator demodulates the low frequency input from the first carrier frequency to thereby generate the response signal comprising the second carrier frequency and the low frequency input. The demodulator preferably includes a pyroelectric demodulator, a piezoelectric demodulator, or a detector diode. The demodulator preferably has a frequency response less than the first carrier frequency but greater than the second carrier frequency.