Optics and Electronics Seminar

AP483 & AMO Seminar presents "Accelerated Scaling to Rapid Open-Air Fabrication of Durable Perovskite Solar Modules"

Topic: 
Accelerated Scaling to Rapid Open-Air Fabrication of Durable Perovskite Solar Modules
Abstract / Description: 

Organic-inorganic metal halide perovskites have seen a resurgence in interest due to unprecedented gains in power conversion efficiency (PCE). Perovskite solar cells, however, suffer from several stability challenges including thermomechanical reliability and moisture sensitivity, which are not competitive with the stability of c-Si modules that exhibit 25-service lifetimes.

We first review results from extensive studies involving an international collaboration on the inherent thermomechanical challenges for reliability of a wide range of planar and mesoporous perovskite solar cells including the role of perovskite and charge transport layer compositions. Trade-offs between efficiency and reliability, meaning maximal conversion efficiencies often come at the expense of mechanical reliability and long-term stability, are discussed.

We next consider accelerated scaling strategies to rapid open-air fabrication of durable perovskite solar modules with improved inherent perovskite and charge transport layer performance and thermal stability. We consider strategies to improve charge transport layers with a concomitant increase in device efficiency. Importantly, we demonstrate that mechanically robust perovskite films can be cured with an open-air atmospheric plasma discharge on large-scale substrates, and at linear deposition rates exceeding 4 cm/s with improved power conversion efficiency and open-circuit voltages.

Finally, we conclude by reporting on a new concept in solar cell design, the scaffold-reinforced compound solar cell (CSC) with integrated low cost optics which addresses the intrinsic fragility of these materials with mechanically reinforcing internal scaffolds. These developments mitigate the foremost barriers to wide-scale commercial deployment, namely perovskite module manufacturing and reliability, providing momentum towards the goal of 0.02 $/kWhr that exceeds even the most aggressive predictions for new silicon PV production and a pathway to tandems.


 

AP 483 Optics and Electronics Seminar

Prof. Olav Solgaard, Organizer Fall 2019

 

AMO Seminar Sub-Series first Monday of each month)

Monica Schleier-Smith, Organizer Fall 2019

 

Date and Time: 
Monday, November 11, 2019 - 4:00pm to Tuesday, November 12, 2019 - 3:55pm
Venue: 
Spilker 232

AP483 & AMO Seminar presents "New Ion Qubits"

Topic: 
New Ion Qubits
Abstract / Description: 

AP 483 Optics and Electronics Seminar

Prof. Olav Solgaard, Organizer Fall 2019

 

AMO Seminar Sub-Series first Monday of each month)

Monica Schleier-Smith, Organizer Fall 2019

 

Date and Time: 
Monday, November 4, 2019 - 4:00pm to Tuesday, November 5, 2019 - 3:55pm
Venue: 
Spilker 232

AP483 & AMO Seminar presents "A glimpse into the dark world of excitons in 2D semiconductors Via time--resolved µ-ARPES"

Topic: 
A glimpse into the dark world of excitons in 2D semiconductors Via time--resolved µ-ARPES
Abstract / Description: 

About a decade ago, the discovery of monolayers of transition metal dichalcogenides opened a new frontier in the study of optically excited states in semiconductors, and related opto-electronic technologies. These materials exhibit a plethora of robust excitonic states, such as bright excitons at the K & K' valleys, momentum- and spin-forbidden dark excitons, and hot excitons. Optics-based experiments have revealed much about the bright excitonic states, but they remain largely unable to access their valley character, their scattering channels into other valleys within the Brilloin Zone, and the nature of the dark states in these valleys. Angle-Resolved Photoemission Spectroscopy (ARPES) based techniques would be ideal to access the valley character, and momentum-resolved scattering channels of photoexcited states in 2D semiconductors. But these are very challenging experiments to perform on the typically-available, micron-scale, 2D semiconductors. In today's talk, I will discuss the challenges involved, and progress made in my lab to date towards this aim. Any maybe – if time permits – we will end with an entertaining peek into the 'quantum psychology of dark excitons'!


 

AP 483 Optics and Electronics Seminar

Prof. Olav Solgaard, Organizer Fall 2019

 

AMO Seminar Sub-Series first Monday of each month)

Monica Schleier-Smith, Organizer Fall 2019

 

Date and Time: 
Monday, October 28, 2019 - 4:00pm to Tuesday, October 29, 2019 - 3:55pm
Venue: 
Spilker 232

AP483 & AMO Seminar presents "Waves, Modes, Communications and Optics - Just How Many Different Light Beams are There?"

Topic: 
Waves, Modes, Communications and Optics - Just How Many Different Light Beams are There?
Abstract / Description: 

There are many useful ways we can think about optics and waves. “Modes,” like resonator modes or propagating modes in fibers, can give particularly powerful and simple descriptions. We then only need amplitudes of a few functions rather than field values at each of a large number of points. But, for scattering from complex nanophotonic structures or use of multiple beams or waves in space to send more information, these resonator or propagating modes are not enough, and can lead to confusion and even major error (for example, in correctly counting the number of “channels” we have to communicate). We need to think about scattering or communicating waves from some source space to some receiving space. That means we need pairs of functions, one in each space. Fortunately, there are elegant and efficient ways of establishing these pairs, both mathematically and physically. Once we do so, we find many simple heuristic behaviors; we can correctly count numbers of usable channels, establishing clear limits; and we can find the “right” fundamental basis pairs for describing optical systems. That basis is fundamental because it leads, for example, to new “Kirchhoff” radiation laws and a simpler “Einstein A&B” coefficient argument, both of which work mode by mode, but only for these new basis function pairs. Along the way, we establish a new “M-gauge” for electromagnetism and an elegant quantization of the electromagnetic field without arbitrary “boxes.” The talk is summarizing a recent paper [1] that introduces all of the necessary math, physics, and results.


 

Prof. Olav Solgaard, Organizer Fall 2019

AMO Seminar Sub-Series first Monday of each month)

Monica Schleier-Smith, Organizer Fall 2019

This seminar series is sponsored by Ginzton Laboratory, SPRC, Applied Physics, Physics, and HEPL. 

Date and Time: 
Monday, October 21, 2019 - 4:00pm to Tuesday, October 22, 2019 - 3:55pm
Venue: 
Spilker 232

AP483 & AMO Seminar presents "Photonics in Computing"

Topic: 
Photonics in Computing
Abstract / Description: 

In the 1980s, optical computing emerged as an extremely active area of research promising immense parallelism and signal processing capabilities. Optical neural networks exploited Fourier transform, convolution, and nonlinear elements to demonstrate matrix multiplication, pattern recognition, and associative memory, capabilities. By the 1990s, however, the field of optical computing died. Psaltis wrote in his 1990 article that optical computing was dead because of (a) the lack of practical devices that can be integrated and because there was (2) insufficient knowledge of complex neural networks. Fast-forwarding to today, we find that (a) integrated circuits can contain heterogeneous nano-scale photonic and electronic components utilizing semiconductor industry ecosystems, and (b) new artificial neural network algorithms can imitate or even surpass the capabilities of humans. We discuss possible new directions in computing exploiting the nonlinearity of nanoelectronics and the parallelism of nanophotonics. We will cover two platforms: (1) brain-inspired spiking-photonic-neuromorphic computing utilizing embedded 3D photonic-electronic integrated circuits and (2) photonic-FPGA utilizing reconfigurable 3D photonics. Prospects of future computing systems including such photonic computing modules will also be discussed.


 

AP 483 Optics and Electronics Seminar

Prof. Olav Solgaard, Organizer Fall 2019

 

AMO Seminar Sub-Series first Monday of each month)

Monica Schleier-Smith, Organizer Fall 2019

 

Date and Time: 
Monday, October 14, 2019 - 4:00pm to Tuesday, October 15, 2019 - 3:55pm
Venue: 
Spilker 232

AP483 & AMO Seminar presents "Splitting a Bose-Einstein Condensate Enables EPR Steering and Simultaneous Readout of Conjugate Observables"

Topic: 
Splitting a Bose-Einstein Condensate Enables EPR Steering and Simultaneous Readout of Conjugate Observables
Abstract / Description: 

AP 483 Optics and Electronics Seminar

Prof. Olav Solgaard, Organizer Fall 2019

 

AMO Seminar Sub-Series first Monday of each month)

Monica Schleier-Smith, Organizer Fall 2019

Date and Time: 
Monday, October 7, 2019 - 4:00pm to Tuesday, October 8, 2019 - 3:55pm
Venue: 
Spilker 232

AP483 & AMO Seminar presents "Adventures with Angular Momenta of Near Field Photons"

Topic: 
Adventures with Angular Momenta of Near Field Photons
Abstract / Description: 

AP 483 Optics and Electronics Seminar

Prof. Olav Solgaard, Organizer Fall 2019

 

AMO Seminar Sub-Series first Monday of each month)

Monica Schleier-Smith, Organizer Fall 2019

 

Date and Time: 
Monday, September 30, 2019 - 4:00pm to Tuesday, October 1, 2019 - 3:55pm
Venue: 
Spilker 232

SCIEN Colloquium and EE 292E present "Snapshot multispectral imaging from a different angle"

Topic: 
Snapshot multispectral imaging from a different angle
Abstract / Description: 

Combining photography and spectroscopy, spectral imaging enables us to see what no traditional color camera has seen before. The current trend is to miniaturize the technology and bring it towards industry. In this talk, I will first give a general introduction to the most common pitfalls of spectral imaging and the challenges that come with miniaturization. Major pitfalls include balancing cross-talk, quantum efficiency, illumination and the optics. Miniaturization has become possible thanks to the monolithic per-pixel integration of thin-film Fabry-Pérot filters on CMOS imaging sensors. I will explain the difficulty of using these cameras with non- telecentric lenses. This is a major concern because of the angular dependency of the thin-film filters. I will demonstrate how this important issue can be solved using a model-based approach.

Date and Time: 
Wednesday, June 12, 2019 - 4:30pm
Venue: 
Packard 101

OSA/SPIE, SPRC and Ginzton Lab present "Effective medium approach towards topological photonics"

Topic: 
Pandora and Prometheus: Science, Scientists, and Society
Abstract / Description: 

As researchers in photonics we have both opportunities to positively impact people's lives and responsibilities to assist in ethical integration of these important new and disruptive technologies into modern society. While photonics provides solutions to critical global issues, such as key technology for measuring the environment and mitigating the impact of climate change, we are also developing new capabilities, which test society's legal and moral frameworks. Photonics enables the internet and social networking, high throughput sequencing of the human genome, pre-implantation testing of human embryos, measurement and control of neural networks in vivo—advances which present significant ethical challenges.

In addition, as scientists we are part of a global research community with the common goal of openly sharing our knowledge world-wide. Knowledge gives competitive and strategic advantages to those having access to it, leading to government pressure to limit free access to and unrestricted dissemination of scientific research. How do we reconcile our national responsibilities and loyalties with our responsibilities as members of the global scientific community to openly share our knowledge? These pressures become particularly acute when most of our research funding comes from federal/national sources.

Both students and faculty are welcome and encouraged to participate in an open discussion of these topics over lunch.

Date and Time: 
Thursday, June 6, 2019 - 12:00pm to Friday, June 7, 2019 - 11:55am
Venue: 
Spilker 232

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