Abstracts Book - IMRC 2018

• SC6-P001
THERMAL CARACTERIZATION OF N-TYPE POROUS SILICON AS A
FUNCTION OF ETCHING TIME
Alejandro Rojas 1 , Uriel Nogal 2 , Joel Hernandez 2 , Jose Bruno Rojas Trigos 1 , Ernesto Marin
Moares 1 , José Antonio Calderón Arenas 1
1 Centro de Investigación en Ciencia Aplicada y Tecnología Avanzada, Legaría, IPN,
Instrumentación y caracterización, Mexico. 2 Consejo Nacional de Ciencia y Tecnologia -
CONACYT, Instituto Politécnico Nacional, Centro de Investigación en Ciencia Aplicada y
Tecnología Avanzada, Unidad Legaria., Mexico.
Taking into consideration the two-layered model for the effective thermal
diffusivity of n-type porous silicon samples elaborated, by means of
electrochemical etching, it was determinate thermal diffusivity, thermal
conductivity and heat capacity of the porous layer as a function of the etching
time. The frequency domain photoacoustic technique in a heat transmission
configuration was used in order to obtain the measured values of the effective
thermal diffusivity of each sample. The thickness of the porous layer was
obtained by means of optical microscopy. Lateral and frontal microstructure
were analyzed by scanning electronic microscopy. The experimental results of
the effective thermal diffusivity of samples show a monotone decrease in its
value 0.88 cm 2 /s, for silicon without attack, until 0.25 cm 2 /s for porous silicon
with 30 minutes of electrochemical attack. By using the two-layered model,
based to the concept of effective thermal resistance for a series two-layered
system, and fitting it to the experimental data were obtained the average values
of thermal conductivity and thermal diffusivity of porous layer in the porous
silicon samples. Finally, each effective thermal diffusivity value, corresponding
to each sample elaborated in the different attack times used, were obtained the
thermal conductivity and thermal diffusivity of porous layer as a function of the
attack time of the electrochemical elaboration process, and these results the
corresponding values of heat capacity were obtained.
Keywords: Photoacustic technique, porous silicon, thermal properties
Presenting authors email: marroquin-m@hotmail.com