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Offers : 2

(filled) Study of potential fluctuations in thin film solar cells

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Start date : 01/10/2017

offer n° IMEPLaHC-05242017-CMNE

                                                                             ED EEATS – THESIS TOPIC 2017 :
Study of potential fluctuations in thin film solar cells

Start date : October 2017
Offer n° IMEPLaHC-05242017-CMNE
PhD position 2017¬-2020
The application must be received before 2017, June 7th

PROJECT DESCRIPTION:
CuZnSnSSe (CZTS) kesterite compounds are promising candidates for third generation thin film solar cells. Such technology is environment-friendly as only composed of earth abundant and non-toxic elements. However, up to now, contrary to more mature CdTe and CIGS devices, the conversion power efficiency of CZTS solar cells does not allow an industrial development. One of the main performance limitations could come from potential fluctuations induced by a large concentration of intrinsic defects in the CZTS alloys.

The objective of this thesis is to quantitatively analyze the potential fluctuations in these compounds and to identify their effect on the device performance. Two experimental and complementary techniques will be used: optical spectroscopy and electrical measurements. The applicant will carry out photoluminescence excitation spectra and time resolved spectroscopy in order to precisely evidence the presence of band tails and localized states. Secondly, admittance spectroscopy will be used to investigate the response of deep traps in the materials. In both cases, the data interpretation will be associated with models taking into account the potential fluctuations. Finally the results will be confronted to the performance of the solar cells.

 DESIRED SKILLS
Solid knowledge in solid-state physics and semiconductor technology
The candidate must hold a master degree (equivalent to a master M2R in France) or an equivalent university degree eligible for the EEATS Doctoral School of Université Grenoble Alpes.

DETAILS
Thesis advisors: Frédérique Ducroquet (IMEP-¬LaHC) – Henri Mariette  (Institut Néel/INAC)
Funding: Doctoral Grant
Thesis starting date: October/November 2017
Thesis duration: 3 years
 Keywords : Photovoltaics, solar cells, electrical measurement, optical spectroscopy
•    Laboratories : IMEP-LaHC – Grenoble
•    Contact : ducroquet@minatec.inpg.fr

 

  • Keywords : Engineering science, Electronics and microelectronics - Optoelectronics, FMNT, IMEP-LaHc
  • Laboratory : FMNT / IMEP-LaHc
  • CEA code : IMEPLaHC-05242017-CMNE
  • Contact : ducroque@minatec.grenoble-inp.fr
  • This Thesis position has been filled. Thank you for your interest

(filled) Sharp-Switching Z2-FET Device: Novel applications, Scaling, Reliability and Variability

Mail Sélection

Start date : 01/09/2017

offer n° IMEPLaHC-05242017-CMNE

                                                                                                      PhD Thesis : Registration DEADLINE on June 13th, 2017

                                                  Sharp-Switching Z2-FET Device: Novel applications, Scaling, Reliability and Variability  

Thesis co-advisorsMaryline Bawedin, IMEP-LAHC,
Joris Lacord, CEA-LETI,
Jacques Cluzel, CEA-LETI
Sorin Cristoloveanu, CNRS, IMEP-LAHC

Contacts: Maryline Bawedin, IMEP-LAHC,
Joris Lacord, CEA-LETI,

External cooperations: Univs. of Glasgow, Fudan (China), San Diego, Brown (USA) and Granada, STMicroelectronics.

The Z2-FET has recently been conceived in Grenoble and fabricated with FD-SOI technology by CEA-LETI and STMicroelectronics. The device is a forward-biased PIN diode, where the current is blocked by energy barriers induced by the front and back gates. A virtual PNPN thyristor with electrostatic doping is emulated. A positive feedback mechanism triggers the current on, leading to an extremely sharp switch (< 1mV/decade) from low OFF to high ON current, even for operation at ~1 V.
Recent studies have been focused on applications related to capacitorless floating-body memory (1T-DRAM) and protection against electrostatic discharge (ESD). The unrivalled performance of Z2-FETs can also be utilized for other novel applications. The research program is three-fold.

1 – Innovative applications. The goal is to design simple logic circuits that take advantage of the vertical switch between OFF and ON states in order to increase the speed and reduce the power. A single-transistor SRAM will also be explored. Finally, the feasibility of Z2-FET-based sensors (chemical, photo, magnetic) will be investigated. The implementation of the device in nanowires will be envisaged.

2 – Device scaling and variability. The minimum length, compatible with state-of-the-art FD-SOI technology, will be determined. The impact of fluctuations in size, film thickness and carrier lifetime will be studied.

3 – Reliability. Despite the advantage of low-voltage operation, carrier injection into the gate dielectric can still cause aging effects. Systematic experiments and TCAD simulations will be performed. This segment of research will also include low-frequency noise measurements. The conclusions of reliability and variability studies will directly apply to the optimization of memories and ESD devices.

The aim of this PhD project is ambitious at the fundamental science level and application-oriented. The research will require strong interaction between various fields of expertise: physics of semiconductor devices, electrical characterization, TCAD simulations and physics-based modeling. Candidates with previous experience in these fields will be highly appreciated. Scientific talent and strong motivation are key criteria of selection. The expertise gained during the PhD will lead not only to numerous publications but also to a successful professional career.

Related publications from IMEP:

H.El DIRANI, K. LEE, M. S. PARIHAR, J. LACORD, S. MARTINIE, J.-C. BARBE, X. MESCOT, P. FONTENEAU, P. GALY, F. GAMIZ, Y. TAUR, S. CRISTOLOVEANU, M. BAWEDIN    
Ultra Low-Power 1T-DRAM in FDSOI Technology, 20th Conference on “Insulating Films on Semiconductors”, 2017, Germany.

J. WAN, C. LE ROYER, A. ZASLAVSKY, S. CRISTOLOVEANU
A compact capacitor-less high-speed DRAM using field effect-controlled charge regeneration.
IEEE Electron Device Letts., 33, n◦ 2, 179{181 (2012)

M. BAWEDIN, S. CRISTOLOVEANU, D. FLANDRE
A capacitor-less 1T-DRAM on SOI based on double gate operation.
IEEE Electron Device Letts., 29, n± 7, 795–798 (2008)

J. WAN, S. CRISTOLOVEANU, C. LE ROYER, A. ZASLAVSKY
A feedback silicon-on-insulator steep switching device with gate-controlled carrier injection.
Solid-State Electronics, 76, 109{111 (2012)

J. WAN, A. ZASLAVSKY, C. LE ROYER, S. CRISTOLOVEANU
A systematic study of the sharp-switching Z2-FET device : from mechanism to modeling and
compact memory applications.
Solid-State Electronics, 90, 2{11 (2013)

H. EL DIRANI, Y. SOLARO, P. FONTENEAU, C.-A. LEGRAND, D. MARIN-CUDRAZ,
D. GOLANSKI, P. FERRARI, S. CRISTOLOVEANU
A band-modulation device in advanced FDSOI technology : sharp switching characteristics.
Solid-State Electronics, 125, 103{110 (2016)

  • Keywords : Engineering science, Electronics and microelectronics - Optoelectronics, FMNT, IMEP-LaHc
  • Laboratory : FMNT / IMEP-LaHc
  • CEA code : IMEPLaHC-05242017-CMNE
  • Contact : maryline.bawedin@minatec.grenoble-inp.fr
  • This Thesis position has been filled. Thank you for your interest
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