Finished temperature-dependence photoluminescence (PL) measurements...

So tired... finally finished TD-PL just now, from 5K to 300K (10K increment for 5K-100K & 20K increment for 100K-300K). There's 5 samples to measure... actually, it's not the sample which make it hard, but the temperature increment which make it very boring measurement. At first, I had to put my samples into a cryostat, cools the cryostat using liquid Helium until it reaches 5K, and increase the temperature according to the measurement parameter using a heater. And, there's a lot of waiting to get the temperature stabilized, before doing the photoluminescence (PL) measurement.

What makes it a tiring measurement is... there was problem with the diffusion pump when I vacuum the cryostat last night (after putting my sample in). Even after waiting for 2 hours, the pressure still at 2 x 10^(-2) Pa. It should be around 1 x 10^(-4) Pa after 40 minutes pumping...

Then, when it reached 5K this morning, I found that the He-Cd (helium-cadmium) laser [used to excite electron in MQW (multi-quantum-well) structure of my sample] didn't reflected properly / passing properly through mirror / lenses on the optical configuration. The worse thing is I found 2 laser spot on my sample, even though there's only 1 laser used in the configuration. I think somebody has accidentally touched the mirror/lenses on the optical table... I was soooooooooo ANGRY!!! But, who? Arghhh...

Fortunately, I fixed the mirror direction on the optical table to get 1 laser spot on my sample... fortunately... seems like it's ok. Dr. Ishikawa must be sooo angry if he found that thing happened again. Everybody who do PL must be angry if he/she found the laser is reflected to different direction... it's normal thing in this field. But, who did it? Hmm... no idea... maybe those guys... (no more comments)

Okay, I've to go home... so tired. I've to spend many hours to analyze the PL data...

Just hoping I could sleep well tonight... Insya'Allah.

~~~ So happy to see a mail from Chongqing in my mailbox just now :) ~~~