editor's blog
Subscribe Now

Piezo… what?

The piezoelectric effect is pretty straightforward. With certain crystals, if you apply strain, the separation of dipoles in the crystal will set up a piezopotential.

Let’s take that one step further by making contacts on either end of a nanowire made of an appropriate material – in particular, ZnO, but potentially other so-called “wurtzite” semiconductors. Put a potential across is and use mechanical stress in the nanowire to modulate the current: you’ve basically got a FET, with the nanowire acting as a mechanical gate.

Those contacts are Schottky contacts, and the strain allows the Schottky barrier to be raised. But if you shine an appropriate laser on the contact, you can create electron-hole pairs, lowering the Schottky barrier, and even making the contact Ohmic instead.

This three-way interplay between the piezopotential created by strain, the optical excitation, and the transport properties of the semiconductor is referred to as piezophototronics. Say it slowly until you get used to it so you don’t hurt yourself.

How is that useful? Well, for one thing, it can be used, as was just demonstrated at Georgia Tech, to increase the performance of a GaN LED by forming a junction between a GaN film and a ZnO nanowire. The interface formed a p-n junction, with the GaN being the p side and the nanowire being the n side.

By straining the nanowire, they could tune the charge transport and effectively increase the rate of electron-hole recombination, increasing the overall efficiency by 4 times.

That’s the condensed version, the bottom line. You can get more details in their recent release.

Leave a Reply

featured blogs
Sep 22, 2021
3753 Cruithne is a Q-type, Aten asteroid in orbit around the Sun in 1:1 orbital resonance with the Earth, thereby making it a co-orbital object....
Sep 21, 2021
Placing component leads accurately as per the datasheet is an important task while creating a package footprint symbol. As the pin pitch goes down, the size and location of the component lead play a... [[ Click on the title to access the full blog on the Cadence Community si...
Sep 21, 2021
Learn how our high-performance FPGA prototyping tools enable RTL debug for chip validation teams, eliminating simulation/emulation during hardware debugging. The post High Debug Productivity Is the FPGA Prototyping Game Changer: Part 1 appeared first on From Silicon To Softw...
Aug 5, 2021
Megh Computing's Video Analytics Solution (VAS) portfolio implements a flexible and scalable video analytics pipeline consisting of the following elements: Video Ingestion Video Transformation Object Detection and Inference Video Analytics Visualization   Because Megh's ...

featured video

Maxim Integrated is now part of Analog Devices

Sponsored by Maxim Integrated (now part of Analog Devices)

What if we didn’t wait around for the amazing inventions of tomorrow – and got busy creating them today?

See What If: analog.com/Maxim

featured paper

An Engineer's Guide to Designing with Precision Amplifiers

Sponsored by Texas Instruments

This e-book contains years of circuit design recommendations and insights from Texas Instruments industry experts and covers many common topics and questions you may encounter while designing with precision amplifiers.

Click to read more

featured chalk talk

SN1000 SmartNIC

Sponsored by Xilinx

Cloud providers face a variety of challenges with moving data from one place to another. In modern data centers, flexibility is a key consideration - on par with performance. Software-defined hardware acceleration offers a major breakthrough in flexibility. In this episode of Chalk Talk, Amelia Dalton chats with Kartik Srinivasan of Xilinx about the details of Smart NICs with the new Alveo SN1000 with composable hardware.

Click here for more information about the Alveo SN1000 - The Composable SmartNIC