The main objective of the project is to optimize the pyroelectric properties of the PZT thin films deposited on buffered Si wafers. Specifically, the following aspects will be addressed:

-       Optimization of the metallic contact in order to reduce the leakage current and to maximize the pyroelectric response. Metals forming good rectifying contacts on PZT are envisaged, such as Cu, Ir, Ru, or conducting oxides as SrRuO3 (SRO). Another aspect that will be addressed is the emissivity of the top contact, the one exposed to the thermal (IR) radiation. Special patterning or coating of the top contact will be envisaged in order to increase the emissivity towards unity (e.g. using carbon nanotubes or carbon dots). Nobel metals will be avoided as they are costly and do not form good contacts on textured PZT films.

-       Optimization of the pyroelectric response by strain and doping engineering. The novelty in this case is to deposite successive layers at different temperatures in order to induce strain gradients that, in turn, can induce internal electric fields activating secondary contributions to the pyroelectric effect. Another novel approach is to use super-lattices of PZT materials with different compositions, as for example tetragonal PZT mixed with antiferroelectric PbZrO3. Finally, intermediate layers reducing the transition temperature can be introduced in order to maximize the pyroelectric response around room temperature, as for example SrTiO3 mixed with PZT.

Suspended pyroelectric elements will be manufactured at the end, capitalizing on the knowledge gained on the quality of the contacts and the best composition/growth procedure that leads to maximum pyroelectric response. Pixel like detectors will be manufactured by integrating the active element with the impedance converter (a field effect transistor or an operational amplifier).

Book chapter:

Electrical Properties of Epitaxial Ferroelectric Heterostructures

Author(s): Andra G. Boni, Cristina Chirila, Raluca Negrea,Cornel Ghica, Iuliana Pasuk, Ioana Pintilie and Lucian Pintilie

Editura Intech

Acknowledgements. The authors acknowledge the financial support of the Romanian Ministry of Education-Executive Unit for Funding High Education, Research, Development and Innovation (MENUEFISCDI) through the Nucleus Program PN16-4801; the Idea-Complex Research Grant

PN-II-ID-PCCE-2011-2-0006 (Contract No. 3/2012); the IFA-CEA (Contract No. C503/2016);

and the CNCS-UEFISCDI Project of PN-II-PT-PCCA-2013-4-0470 (Contract No. 238/2014).

Capitolul cuprinde descrierea pe larg a metodei de depunre, caracterizarea structurala si electrica a filmelor de PZT cu raport de Zr/Ti 52/48 realizate prin PLD pe substrat de Si cu strat buffer de STO realizat de partenerul francez prin MBE si comportamentul acestora functie de electrodul superior, rezultatele sunt prezentate comparativ cu structuri similare obtinute pe substrat monocrtistalin de STO.

Conferinte:

1)      PZT thin films on Si for pyroelectric applications

C. Chirila, G.Le Rhun, M.Botea, L. Hrib, A. Boni, A.Iuga, I Pintilie^, L. Pintilie

conferinta EMRS Spring Meeting 2017, Strasbourg, Franta in periada 21-26 mai,

Prezentare orala

2)      Pulsed laser deposition of epitaxial ferroelectric thin films and

 their potential applications

C. Chirila, A. Boni,  M. Botea, L. Hrib, L. Trupina, I. Pasuk, R. Negrea, I. Pintilie, and L. Pintilie

conferinta ROCAM `17, Bucuresti, Romania in perioada 11-14 Iulie 2017

Prezentare orala

3) Epitaxial growth of ferroelectric thin films and their potential applications

1. Chirila, A. Boni , M. Botea, L. Hrib, L. Trupina, I. Pasuk, R. Negrea, I. Pintilie, L.Pintilie, G.Le Rhun

EMS Meeting on Epitaxy, 18-23 Iunie 2018, Viena, Austria

Lectie invitata

4) Ferroelectric thin films epitaxially grown and their potential applications

1. Chirila, A. Boni , M. Botea, L. Hrib, L. Trupina, I. Pasuk, R. Negrea, I. Pintilie, L. Pintilie,

6th Venice International School on Lasers in Materials Science – SLIMS, 8-15 Iulie 2018, Venetia, Italia

Prezentare orala

In cadrul acestei scoli directorul de proiect a participat la competia „Roger Kelly Award”, unde a obtinut premiul III Rising Stars. Premiu a fost acordat pentru contributii relavante in domeniul interactei laser-materie si in competitie au fost 30 de candidati din diferite tari.