Conventional square and triangular LEDs

[greynoon]

Could someone please differentiate this to me? "Why Conventional square LEDs are less efficient than triangular LEDs.

If any of you guys could help me out, or point me in the right direction, it would be a great help!

Thank you in advance!

 

[berkeman]

Could someone please differentiate this to me? "Why Conventional square LEDs are less efficient than triangular LEDs.

If any of you guys could help me out, or point me in the right direction, it would be a great help!

Thank you in advance!

Yikes. I have an idea, but I need to know if this is a homework/coursework question first. We handle posts differently if they are for homework/coursework.

What is the context of the question? What are your thoughts on it so far? What factors go into the efficiency of an LED, from electrical energy to the final light energy that makes it out into the air?

 

[greynoon]

Yikes. I have an idea, but I need to know if this is a homework/coursework question first. We handle posts differently if they are for homework/coursework.

What is the context of the question? What are your thoughts on it so far? What factors go into the efficiency of an LED, from electrical energy to the final light energy that makes it out into the air?

This question i asked is neither coursework nor homework. I came along this question after perusing on some past year assignments which really triggered me. I just want to have a knowledge of the diffrences in the LEDs.
My thoughts so far are: It has something to do with total internal reflection or snells law!

 

[berkeman]

My thoughts so far are: It has something to do with total internal reflection or snells law!

That was my thought as well. The most efficient would be the rounded top traditional LED shape (that's why they are round in the first place). To contrast the square and triangular shapes, you'd need to do some 3-D ray tracing to see what the exit path options looked like.

 

[dlgoff]

Substrates that are transparent to the emitted wavelength, and backed by a reflective layer, and light spreading layer, increase the LED efficiency. The refractive index of the package material should match the index of the semiconductor, otherwise the produced light gets partially reflected back into the semiconductor, where it may be absorbed and turned into additional heat, thus lowering the efficiency.

http://en.wikipedia.org/wiki/LED#Light_extraction"