What is the goal of applying forward bias in semiconductors?

Applying forward bias in semiconductors primarily aims to facilitate the flow of current through the device. When a semiconductor, such as a diode, is forward-biased, the potential barrier at the junction is lowered, allowing charge carriers (electrons and holes) to recombine more readily. This recombination process under forward bias is essential in opto-electronic devices, such as light-emitting diodes (LEDs) and laser diodes, as it leads to photon emission—effectively producing an optical output from an electrical input.

In contrast to this, the other options do not align with the fundamental principle of forward bias. Creating a junction barrier is more characteristic of reverse bias, where the barrier is increased to inhibit current flow. Increasing resistance is also contrary to the forward bias effect, as forward bias decreases resistance and allows for current flow. Similarly, decreasing temperature is irrelevant in the context of applying forward bias since biasing relates to the junction's electrical potential rather than thermal conditions. Thus, the correct answer focuses on harnessing the forward bias effect to generate optical output, which is central to the function of many opto-electronic devices.