## Erik Johnson

Erik Johnson is a CNRS researcher at the LPICM, located at the Ecole Polytechnique.Â In addition to his passion for teaching the physics and engineering of solar cells, his research interests focus on novel plasma processing for semiconductor devices.Â He is the current holder of the ANR Industrial Research Chair "PISTOL", in collaboration with Total.

**Presentation :**

**Moodle :**

#### PHY558B - Physics and Engineering of Photovoltaic Devices (2020-2021)

Course Outline:

- General Introduction, “What is Photovoltaics?” Solar energy resource, current use of PV
- Introduction to the physics of crystalline semiconductors: band structure, intrinsic and extrinsic semiconductors, quasi-Fermi levels.
- Transport phenomena in semiconductors, recombination, the p-n junction. The photovoltaic effect
- Material junctions and energy band-diagrams. Metal/semiconductor contacts. Heterojunctions
- Optical absorption, solar spectrum and EQE. Solar cell efficiency limits. Equivalent circuit model.
- Crystalline silicon (c-Si) PV technology and operation. Basic and high efficiency c-Si cell architectures.
- PV technology overview and the cost of PV
- Modules, concentration, and advanced concepts

**Niveau requis :**

Recommended courses for Ecole polytechnique's students :

PHY430 - Advanced Quantum Physics and PHY433 - Statistical Physics**Langue du cours :** English**Credits ECTS :** 5

Course Outline:

- General Introduction, “What is Photovoltaics?” Solar energy resource, current use of PV
- Introduction to the physics of crystalline semiconductors: band structure, intrinsic and extrinsic semiconductors, quasi-Fermi levels.
- Transport phenomena in semiconductors, recombination, the p-n junction. The photovoltaic effect
- Material junctions and energy band-diagrams. Metal/semiconductor contacts. Heterojunctions
- Optical absorption, solar spectrum and EQE. Solar cell efficiency limits. Equivalent circuit model.
- Crystalline silicon (c-Si) PV technology and operation. Basic and high efficiency c-Si cell architectures.
- PV technology overview and the cost of PV
- Modules, concentration, and advanced concepts

**Niveau requis :**

Recommended courses for Ecole polytechnique students :

PHY430 - Advanced Quantum Physics and PHY433 - Statistical Physics**Course Language :** English**ECTS Credits :** 5

#### PHY661B - Photovoltaic Technologies in Industry (PV Ind) (2020-2021)

This course makes the link between the fundamental physics of photovoltaic devices and the practical reality of selling PV-generated kWh.

It is composed of two parts: (1) an intensive laboratory component (24 hours spent in a research lab) giving students the opportunity to fabricate and test photovoltaic devices in a research environment, and (2) three lectures given by our industrial partners from Total, concerning the PV industry.

This course makes the link between the fundamental physics of photovoltaic devices and the practical reality of selling PV-generated kWh.

It is composed of two parts: (1) an intensive laboratory component (24 hours spent in a research lab) giving students the opportunity to fabricate and test photovoltaic devices in a research environment, and (2) three lectures given by our industrial partners from Total, concerning the PV industry.

#### PHY530 - Refresher Course in Physics (2020-2021)

#### PHY208 - Atoms and Lasers (2020-2021)

Light amplification by stimulated emission

of radiation (laser) holds a unique

place in the heart of physicists. Lasers

are at the same time a spectacular manifestation

of a quantum phenomenon, a

powerful and versatile tool ranging from

industrial applications (laser processing,

telemetry…) to fundamental research

(spectroscopy, cold atoms…) and a

remarkable workbench to acquire a better

understanding of key concepts in physics.

PHY 208 is an introduction to lightmatter

interactions through the intricate

relationship between atoms and lasers.

Importantly, this course will build on

experimental situations, and introduce

models with increasing complexity to

explain the observed results. As the basic

component of a laser is a source of light,

the course will start with basic spectroscopy,

and several atomic models will be

considered (Bohr model, Einstein coefficients,

Schrodinger model, etc.). The

emission of continuous laser light by

such atoms will be described from both

a classical (effective medium) and semiclassical

(population inversion) perspective.

The mirror will then be turned back

on the atoms, and several applications of

laser light revealing the behavior of atoms

will be discussed (Light, Stark and Zeeman

shift, Rabi oscillations etc.). Finally,

some practical perspectives on advanced

laser technologies and applications will be

given.

This course will not add many new physical

concepts, but rather show how results

obtained in previous courses (especially

in optics, classical and quantum mechanics)

can be used. Upon completion of

this course, students will have acquired

key understandings concerning the bilateral

interactions between laser devices

and atoms. They will have understood the

circumstances under which the emission

of useful coherent light can be produced,

and also the information that such light

can provide when analyzing atomic systems.

They will also be able to identify the

relevance, necessity, and limitations that

classical and quantum models display

when analyzing problems in this field.

They will also gain familiarity with some

laser device technologies.

Light amplification by stimulated emission of radiation (laser) holds a unique place in the heart of physicists. Lasers are at the same time a spectacular manifestation of a quantum phenomenon, a powerful and versatile tool ranging from industrial applications (laser processing, telemetry...) to fundamental research (spectroscopy, cold atoms,...) and a remarkable workbench to acquire a better understanding of key concepts in physics.

PHY208 is an introduction to light-matter interactions through the intricate relationship between atoms and lasers. Importantly, this course will build on experimental situations, and introduce models with increasing complexity to explain the observed results. As the basic component of a laser is a source of light, the course will start with basic spectroscopy, and several atomic models will be considered (Bohr model, Einstein coefficients, Schrodinger model, etc.). The emission of continuous laser light by such atoms will be described from both a classical (effective medium) and semi-classical (population inversion) perspective. The mirror will then be turned back on the atoms, and several applications of laser light revealing the behavior of atoms will be discussed (Light, Stark and Zeeman shift, Rabi oscillations etc.). Finally, some practical perspectives on advanced laser technologies and applications will be given.

This course will not add many new physical concepts, but rather show how results obtained in previous courses (especially in optics, classical and quantum mechanics) can be used. Upon completion of this course, students will have acquired key understandings concerning the bilateral interactions between laser devices and atoms. They will have understood the circumstances under which the emission of useful coherent light can be produced, and also the information that such light can provide when analyzing atomic systems. They will also be able to identify the relevance, necessity, and limitations that classical and quantum models display when analyzing problems in this field. They will also gain familiarity with some laser device technologies.