March 10, 2019

An Interview with Sam Stranks

1 hour 10 minutes

Welcome Dr Sam Stranks, entrepreneur and professor at Cambridge University!

Perovskites

0h 0m 49s

The family is based on the crystal structure

0h 1m 15s

Have been worked on for 2 to 3 decades

0h 1m 44s

Only since 2009 have they been used as a solar cell

0h 2m 36s

Sam's background is physicist

0h 4m 46s

Raised in Australia

0h 6m 23s

Broad undergrad background

0h 7m 0s

Bridged chemistry and physics in Master's program

0h 7m 22s

Worked on removing white wine proteins

0h 7m 32s

The mechanism is similar to how alzheimers blobs together

0h 8m 50s

2007

0h 10m 24s

He got a Rhodes scholarship which meant he ended up going to Cambridge University.

0h 10m 29s

Research included carbon nanotubes

0h 11m 7s

Wrapping polymes around then

0h 11m 21s

Popularity has been dropping

0h 11m 47s

Fullerenes, Graphene both won Nobel prize.

0h 12m 2s

Producing nanotubes is difficult

0h 12m 21s

Dave made a video about a bunkum Kickstarter doing Graphene heaters

0h 12m 34s

Specifically separating out metallic and semiconductor types

0h 12m 47s

Finished PhD 2012

0h 15m 5s

Joined Henry Snaith's group doing dye sensitized solar cells

0h 15m 21s

Reemergence of perovskites

0h 16m 21s

The initial focus was on a dye sensitive cell made out of perovskite

0h 18m 25s

Early efficiency was 3%

0h 18m 56s

The research is done in a place that looks more like a chemistry lab than a semi lab

0h 22m 23s

Solar simulator to replicate the sun

0h 23m 40s

How are perovskites different from solar cells?

0h 25m 34s

Silicon has an indirect bandgap

0h 26m 49s

Multijunctions cells (the kind on satellites) have different absorbers (different colors)

0h 27m 52s

Record silicon efficiency is 27%

0h 28m 21s

Full panel is about 20%

0h 28m 39s

Perovskite is at 23%

0h 29m 5s

Triple junction is 39%

0h 29m 27s

Videos from past guests Sam Zeloof and Jeri Ellsworth

0h 30m 53s

Printed solar cells

0h 32m 4s

ABX3

0h 34m 4s

Thickness only needs to be half a micron

0h 34m 41s

The name 'perovskite solar cell' is derived from the ABX3 crystal structure of the absorber materials, which is referred to as perovskite structure. The most commonly studied perovskite absorber is methylammonium lead trihalide (CH3NH3PbX3, where X is a halogen atom such as iodine, bromine or chlorine), with an optical bandgap between 1.5 and 2.3 eV depending on halide content. Formamidinum lead trihalide (H2NCHNH2PbX3)

0h 35m 56s

Currently using Indium for the contact, but it's hard to get, running out

0h 36m 13s

Talking through the stack

0h 37m 12s

Bottom electrode is Indium Tin oxide

0h 37m 37s

Then a layer of perovskite

0h 37m 53s

Top layer is organic

0h 38m 37s

Illumnate through the glass,

0h 39m 33s

InSnOx is transparent up to UV

0h 41m 14s

Perovskite absorbs 200-800

0h 41m 28s

Using lasers to test with pulses

0h 44m 57s

Pulses for a 1 ps

0h 45m 7s

Monitor how they recombine and lose energy

0h 45m 38s

What causes a defect?

0h 46m 23s

What actually makes electrons mobile in the ABX3 structure?

0h 49m 15s

Structure is mostly from the B and the X (lead and iodide)

0h 49m 35s

Covalently bonding vs ionic bonding

0h 52m 35s

Other applications being targeted

0h 56m 47s

Light emission (LEDs)

0h 56m 57s

Also using for lasing materials (LASERs)

0h 59m 41s

Want to make an electrically pumped laser

0h 59m 55s

Have been some changes in the A site that stabilize ion migration

1h 1m 55s

Sam is a founder of Swift Solar

1h 2m 29s

The 6 founders had spent time together in Henry Snaith's group

1h 2m 43s

Focusing on making tandem cells

1h 3m 20s

Making a solar sheet

1h 4m 13s

More solar cells in a smaller area

1h 4m 59s

Payback periods

1h 5m 25s

Why hasn't this started on the production side yet?

1h 6m 18s

Solar is coming down to 20 cent per watt

1h 6m 43s

Install costs are still $1 per watt

1h 6m 56s

The lightweight aspects lowers the cost of installation

1h 7m 20s

Sam did a TED talk

1h 8m 13s

Integrated photovoltaics

1h 8m 25s

Group web page

1h 9m 27s

Want to learn more about bandgaps? Check out pveducation.org

1h 9m 33s

Scientific American wrote an article about The Perovskite Boom last year

1h 9m 54s

Sam's lab is taking new students! Reach him via his web page or reach out to him on Twitter (@SamStranks)

1h 11m 59s

Photo: Ryan Lash / TED

...more

View all episodes

By The Amp Hour (Chris Gammell and David L Jones)

4.9

226226 ratings

March 10, 2019

An Interview with Sam Stranks

1 hour 10 minutes

Welcome Dr Sam Stranks, entrepreneur and professor at Cambridge University!

Perovskites

0h 0m 49s

The family is based on the crystal structure

0h 1m 15s

Have been worked on for 2 to 3 decades

0h 1m 44s

Only since 2009 have they been used as a solar cell

0h 2m 36s

Sam's background is physicist

0h 4m 46s

Raised in Australia

0h 6m 23s

Broad undergrad background

0h 7m 0s

Bridged chemistry and physics in Master's program

0h 7m 22s

Worked on removing white wine proteins

0h 7m 32s

The mechanism is similar to how alzheimers blobs together

0h 8m 50s

2007

0h 10m 24s

He got a Rhodes scholarship which meant he ended up going to Cambridge University.

0h 10m 29s

Research included carbon nanotubes

0h 11m 7s

Wrapping polymes around then

0h 11m 21s

Popularity has been dropping

0h 11m 47s

Fullerenes, Graphene both won Nobel prize.

0h 12m 2s

Producing nanotubes is difficult

0h 12m 21s

Dave made a video about a bunkum Kickstarter doing Graphene heaters

0h 12m 34s

Specifically separating out metallic and semiconductor types

0h 12m 47s

Finished PhD 2012

0h 15m 5s

Joined Henry Snaith's group doing dye sensitized solar cells

0h 15m 21s

Reemergence of perovskites

0h 16m 21s

The initial focus was on a dye sensitive cell made out of perovskite

0h 18m 25s

Early efficiency was 3%

0h 18m 56s

The research is done in a place that looks more like a chemistry lab than a semi lab

0h 22m 23s

Solar simulator to replicate the sun

0h 23m 40s

How are perovskites different from solar cells?

0h 25m 34s

Silicon has an indirect bandgap

0h 26m 49s

Multijunctions cells (the kind on satellites) have different absorbers (different colors)

0h 27m 52s

Record silicon efficiency is 27%

0h 28m 21s

Full panel is about 20%

0h 28m 39s

Perovskite is at 23%

0h 29m 5s

Triple junction is 39%

0h 29m 27s

Videos from past guests Sam Zeloof and Jeri Ellsworth

0h 30m 53s

Printed solar cells

0h 32m 4s

ABX3

0h 34m 4s

Thickness only needs to be half a micron

0h 34m 41s

0h 35m 56s

Currently using Indium for the contact, but it's hard to get, running out

0h 36m 13s

Talking through the stack

0h 37m 12s

Bottom electrode is Indium Tin oxide

0h 37m 37s

Then a layer of perovskite

0h 37m 53s

Top layer is organic

0h 38m 37s

Illumnate through the glass,

0h 39m 33s

InSnOx is transparent up to UV

0h 41m 14s

Perovskite absorbs 200-800

0h 41m 28s

Using lasers to test with pulses

0h 44m 57s

Pulses for a 1 ps

0h 45m 7s

Monitor how they recombine and lose energy

0h 45m 38s

What causes a defect?

0h 46m 23s

What actually makes electrons mobile in the ABX3 structure?

0h 49m 15s

Structure is mostly from the B and the X (lead and iodide)

0h 49m 35s

Covalently bonding vs ionic bonding

0h 52m 35s

Other applications being targeted

0h 56m 47s

Light emission (LEDs)

0h 56m 57s

Also using for lasing materials (LASERs)

0h 59m 41s

Want to make an electrically pumped laser

0h 59m 55s

Have been some changes in the A site that stabilize ion migration

1h 1m 55s

Sam is a founder of Swift Solar

1h 2m 29s

The 6 founders had spent time together in Henry Snaith's group

1h 2m 43s

Focusing on making tandem cells

1h 3m 20s

Making a solar sheet

1h 4m 13s

More solar cells in a smaller area

1h 4m 59s

Payback periods

1h 5m 25s

Why hasn't this started on the production side yet?

1h 6m 18s

Solar is coming down to 20 cent per watt

1h 6m 43s

Install costs are still $1 per watt

1h 6m 56s

The lightweight aspects lowers the cost of installation

1h 7m 20s

Sam did a TED talk

1h 8m 13s

Integrated photovoltaics

1h 8m 25s

Group web page

1h 9m 27s

Want to learn more about bandgaps? Check out pveducation.org

1h 9m 33s

Scientific American wrote an article about The Perovskite Boom last year

1h 9m 54s

Sam's lab is taking new students! Reach him via his web page or reach out to him on Twitter (@SamStranks)

1h 11m 59s

Photo: Ryan Lash / TED

...more

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An Interview with Sam Stranks

An Interview with Sam Stranks

More shows like The Amp Hour

The Changelog: Software Development, Open Source

This Week in Tech (Audio)

Security Now (Audio)

Software Engineering Daily

Talk Python To Me

SpyCast

SANS Internet Stormcenter Daily Cyber Security Podcast (Stormcast)

Embedded

Smashing Security

Darknet Diaries

Physics World Weekly Podcast

Practical AI

Hackaday Podcast

Latent Space: The AI Engineer Podcast

Robinson's Podcast